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smithsonian contributions to museum conservation • number 5

The Noninvasive Analysis 

of Painted Surfaces

Scientific Impact and Conservation Practice

Edited by

Austin Nevin and Tiarna Doherty
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smithsonian contributions to museum conservation • number 5

The Noninvasive Analysis 

of Painted Surfaces

Scientific Impact and Conservation Practice

Edited by

Austin Nevin and Tiarna Doherty

WASHINGTON D.C.

2016
ABSTRACT

Nevin, Austin, and Tiarna Doherty. The Noninvasive Analysis of Painted Surfaces: Scientific Impact and Conservation 

Practice. Smithsonian Contributions to Museum Conservation number 5, viii + 81 pages, 43 figures, 5 tables, 2016.—While 

nondestructive and microdestructive analytical methods are often essential for the study and understanding of paintings, 

recent development in portable and noninvasive instrumentation has led to growing interest in the applicability of techniques to the study of paintings. Further, as new instrumentation becomes commercially available and more affordable, 

conservators and scientists are able to use noninvasive techniques for monitoring and analysis in new ways. A focus of the 

six papers in these proceedings is the interpretation of analytical results from portable instrumentation.

Cover images, from left: detail of the trapezoidal yellow form crossed by a blue bar showing small areas of exposed 

white underlayer (see Kokkori et al., Figure 5); detail of the Beatus initial on fol. 23v, painted by the Gaibana Master 

(see Ricciardi and Panayotova, Figure 1); and visible light image of sample in cross section from The Dinner (see Fife 

et al., Figure 3). 

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Names: Nevin, Austin, 1978– editor. | Doherty, Tiarna, editor. | Smithsonian Institution Scholarly Press, publisher.

Title: The noninvasive analysis of painted surfaces : scientific impact and conservation practice / edited by Austin Nevin 

and Tiarna Doherty.

Other titles: Non-invasive analysis of painted surfaces | Scientific impact and conservation practice | Smithsonian 

contributions to museum conservation ; no. 5.

Description: Washington, D.C. : Smithsonian Institution Scholarly Press, 2016. | Series: Smithsonian contributions 

to museum conservation, ISSN 1949-2359 ; number 5 | Includes bibliographical references and index.

Identifiers: LCCN 2016027011

Subjects: LCSH: Painting—Conservation and restoration. | Fluorescence spectroscopy. | Paint materials—Analysis. 

| Colorimetry.

Classification: LCC ND1635 .N66 2016 | DDC 751.4--dc23 | SUDOC SI 1.57:5 

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Contents

ACKNOWLEDGMENTS v

INTRODUCTION vii

Quantifying and Mapping Induced Strain in Canvas Paintings Using 

Laser Shearography 1

Philip Klausmeyer, Matthew Cushman, Ivo Dobrev, Morteza Khaleghi, 

Ellery J. Harrington, Xiaoran Chen, and Cosme Furlong

Evidence for the Accumulative Effect of Organic Solvent Treatments on 

Paintings and What to Do about It: A Case Study of Two “Identical” 

Seventeenth-Century Paintings Using Single-Sided Nuclear Magnetic 

Resonance 15

Gwendoline Fife, Bascha Stabik, Bernard Blümich, 

Renè Hoppenbrouwers, and Tyler Meldrum

A Holistic, Noninvasive Approach to the Technical Study of Manuscripts: 

The Case of the Breslau Psalter 25

Paola Ricciardi and Stella Panayotova

Unraveling the History of Two Fifteenth-Century Spanish Panels 37

Marya Albrecht, Melissa Daugherty, Saskia van Oudheusden, 

Lieve d’Hont, Kate Seymour, Michael Rief, Ray Marchant, 

and Erich Uffelmam

Portable X-ray Fluorescence and Infrared Fluorescence Imaging Studies 

of Cadmium Yellow Alteration in Paintings by Edvard Munch and 

Henri Matisse in Oslo, Copenhagen, and San Francisco 53

Jennifer L. Mass, Erich Uffelman, Barbara Buckley, Inger Grimstad, 

Anna Vila, John Delaney, Jugen Wadum, Victoria Andrews, 

Lindsay Burns, Samuel Florescu, and Alyssa Hull

Materials and Meanings: Analyzing Kazimir Malevich’s Painterly Realism 

of a Football Player—Color Masses in the 4th Dimension 65

Maria Kokkori, Stephanie d’Alessandro, Kristin Lister, and 

Francesca Casadio

INDEX 77

Acknowledgments

The conference “The Non-Invasive Analysis of Painted Surfaces: Scientific Impact and Conservation Practice” was presented in partnership with the Lunder 

Conservation Center, the International Council of Museums–Committee for 

Conservation (ICOM-CC) Paintings Working Group and Scientific Research 

Working Group, and the Foundation of the American Institute for Conservation of Historic and Artistic Works. We thank Christopher Wayner, program coordinator at the 

Lunder Conservation Center, for assisting with the organization of the conference that 

was held in early 2014 and for coordinating all of the conference videos that are now 

available online. We thank Ginger Strader, director of the Smithsonian Institution Scholarly Press, and editor Deborah Stultz for their commitment in managing the publication 

of this volume.

Introduction

“The Non-Invasive Analysis of Painted Surfaces: Scientific Impact and 

Conservation Practice” was a conference designed to bring scientists 

and paintings conservators together to share current research. The 

two-day event was hosted by the Lunder Conservation Center at the 

Smithsonian American Art Museum and National Portrait Gallery in Washington, D.C., 

on February 20 and 21, 2014. Presented in partnership with the Lunder Conservation 

Center, the International Council of Museums–Committee for Conservation (ICOM-CC) 

Paintings Working Group and Scientific Research Working Group, and the Foundation 

of the American Institute for Conservation of Historic and Artistic Works, the meeting 

was attended by over 150 people. Current research in the field of conservation was presented by scientists, conservators, and companies that develop instrumentation that has 

compelling applications in the examination and analysis of paintings. Presentations and 

panel discussions were designed to highlight recent technological developments as well as 

challenges in interpreting data. All presentations were recorded and can be viewed online 

(https://www.youtube.com/playlist?list=PL7gn_68Hr4h_qnMshu8PN6wZdPrKoa6sL). 

Selected papers from the conference are presented in this volume. 

A focus of the conference was the presentation of new instrumentation and applications, the integration of imaging and spectroscopic analysis, and the challenging interpretation of analytical results. Although nondestructive and microdestructive analytical 

methods are often essential for the study and understanding of paintings, recent developments in portable and noninvasive instrumentation have led to growing interest in the 

applicability of techniques to the study of paintings for the assessment of the environment and for optimizing conservation treatments. Indeed, as instrumentation becomes 

commercially available and more affordable, conservators and scientists are able to use 

noninvasive techniques for monitoring and analysis in new ways. 

Research by conservators and scientists from different disciplines is found in many 

papers in this volume, as are case studies based principally on the use of nondestructive 

techniques for the study of paintings.

An instrument for the measurement of full-field images of paintings based on 

shearography is presented along with applications to the study of works at the Worcester 

Art Museum by Klausmeyer et al. These and similar optical metrology methods based on 

holographic interferometry are extremely powerful and yield convincing data on the immediate and long-term effects of environmental fluctuations on the surface of paintings. 

Data will surely inform future development of environmental guidelines. 
viii • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

Noninvasive nuclear magnetic resonance (NMR) is employed by Fife et al. in the assessment of two paintings that have 

significantly different treatment history. Data based on nuclear 

spin relaxation can be related to the rigidity of the canvases, 

which are quite different even though both paintings share a 

common stratigraphy. Indeed, the long-term effects of swelling 

of paint during cleaning are suggested to be responsible for the 

modification of the stiffness of the canvas. Nuclear magnetic 

resonance is likely to find other applications to the assessment of 

paintings and their conservation in the future.

In-depth case studies based on technical study of one or 

more paintings on different supports—parchment, wood, and 

canvas—constitute the main group of papers. Although spanning seven centuries, each of the case studies focuses on unique 

interdisciplinary methodologies for addressing specific questions 

related to technique, attribution, pigment degradation, and conservation. A common feature of all the papers presented is the 

need to unite point-like analytical methods with imaging techniques. Indeed, the strength of imaging or scanning techniques 

is that specific areas can be analyzed using point-like techniques, 

and noninvasive data can guide sampling.

Ricciardi and Panayotova present the study of illuminated 

manuscripts, comparing technical data acquired with noninvasive spectroscopy and imaging with codicological and art historical research. Albrecht et al. demonstrate the integration of 

analytical and imaging techniques for the study and attribution 

of fifteenth-century panel paintings. Mass et al. combine pointlike X-ray fluorescence with imaging in different modalities to 

map the degradation of cadmium-based pigments from late 

nineteenth- and early twentieth-century paintings by Edvard 

Munch and Henri Matisse. Kokkori et al. present focused analytical research on a painting by Kazimir Malevich, harnessing a 

range of imaging and analytical techniques, including reflectance 

Fourier transform infrared spectroscopy, to study the composition of the paint he used and the methods he used to execute the 

seemingly simplistic shapes in the Football Player.

The contributions in this volume thus highlight many aspects of the application of noninvasive techniques to the study 

of paintings—their conservation, environment, and technique. 

Conservation science is a multidisciplinary field that relies on 

the close collaboration between conservators, physical scientists, and art historians. Some techniques are commercially 

available today, whereas others are still being developed by engineers and conservators for specific applications both in the 

laboratory and in the museum. There is still a strong need for 

access to instrumentation and expertise for conservators who do 

not have dedicated laboratories, and this is particularly important outside of the museum context. Portable and noninvasive 

techniques, including mobile laboratories, are thus promising 

solutions for the study of paintings when dedicated instrumentation is not present on site. With increased access to instrumentation the role of specialists remains integral to the correct 

interpretation of data gathered from complex art materials that 

have altered over time.

From the range of the six papers in this volume and the 

various applications of noninvasive methods it is clear that there 

is no unique toolkit of techniques or single approach based on 

techniques for the study of paintings and their conservation. The 

inspiring collection of work instead demonstrates ways in which 

conservators and conservation scientists can successfully work 

together. 

Austin Nevin

Istituto di Fotonica e Nanotecnologie

Consiglio Nazionale delle Ricerche

Milano, Italy

Tiarna Doherty

Lunder Conservation Center

Smithsonian American Art Museum

Washington, D.C.
ABSTRACT. Evaluation of museums’ condition standards used for the exhibition of canvas paintings requires a quantitative technique capable of measuring strain induced by changes in temperature, 

relative humidity, and the thermomechanical effects of light, as well as the effects of ambient vibration. This paper presents advances in developing a customized shearography system for temporal 

characterization of strains that occur on canvas paintings when subjected to changes in exhibition 

conditions. The shearography system performs measurements of displacement derivatives along two 

orthogonal shearing directions and is synchronized with an IR camera to provide thermal maps of the 

area analyzed. Innovations incorporated into the system include a real-time temporal phase unwrapping algorithm, high-resolution fast Fourier transform methods to calibrate applied shearing levels, 

and algorithms to produce maps correlated to the temporal domain that locate strain vectors as they 

occur on the surface analyzed. This research also includes methods for isolating thermal-induced 

components from randomly induced mechanical vibrations through integration of IR imaging data. 

As a verification and exploration of the fault detection capabilities of our shearographic system, 

we have performed preliminary experiments that compare measured gradients of displacement with 

slopes of surface topology obtained by reflectance transformation imaging (RTI). Preliminary analysis 

indicates good correspondence between spatial patterns, indicative of surface cracks, in both shearographic and RTI data. The capability of the system to detect discontinuities in paint surfaces as well 

as to measure and map associated strain vectors as a function of changes in condition parameters 

is herein illustrated. Our multidomain approach, incorporating strain, thermal, and topographical 

data, has the potential to inform larger ongoing discussions regarding conservation standards for the 

exhibition of artwork as well as improving defect detection and evaluation of restoration techniques.

INTRODUCTION

Shearography is a full-field, nondestructive, noncontact, optical method that uses 

coherent light to conduct strain and vibration analysis (Hung, 1982). The method is 

highly sensitive for measuring load-induced surface displacement gradients and can effectively detect surface and subsurface discontinuities (Schnars and Jüptner, 1994; Steinchen 

and Yang, 2003; Lee et al., 2014). Although similar to holographic interferometry, 

shearography differs in that instead of measuring displacement, it measures gradients of 

displacement. 

One of the primary advantages of shearography over holography is its relative insensitivity to environmental disturbances. Other advantages include range, mobility, versatility, 

ease, speed, and relative low cost. For these reasons, applications of shearography continue 

to grow, particularly as a method for defect detection in the aerospace, automotive, and 

1 Conservation Department, Worcester Art 

Museum, 55 Salisbury Street, Worcester, Massachusetts 01609, USA.

2

 Center for Holographic Studies and Laser 

micro-mechaTronics, Nanoengineering, Science, 

and Technology, Worcester Polytechnic Institute, 100 Institute Road, Worcester, Massachusetts 01609, USA.

3

 Stanford Biomedical Optics Group, 450 Serra 

Mall, Stanford University, Stanford, California 

94305, USA.

*

 Correspondence: C. Furlong, cfurlong@wpi.edu 

Manuscript received 15 August 2014; accepted 

22 February 2016.

Quantifying and Mapping Induced Strain in 

Canvas Paintings Using Laser Shearography

Philip Klausmeyer,1 Matthew Cushman,1 Ivo Dobrev,2

Morteza Khaleghi,2,3 Ellery J. Harrington,2

 Xiaoran Chen,2

and Cosme Furlong2*
2 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

wind power industries, where the performance of coatings and 

laminated surface construction is critical. 

As a highly sensitive technique for measuring gradients of 

displacement, shearography also has great potential for applications in art conservation (Groves et al., 2009a, 2009b; Sfarra 

et al., 2011; Meybodi et al., 2012; Morawitz et al., 2013). In 

recent years, the majority of shearography-based research into 

art conservation applications has taken place in Europe, with 

the Institute for Technical Optics at Stuttgart University and the 

Foundation for Research and Technology–Hellas (FORTH) in 

Crete, Greece, each being research hotbeds. Most of the research 

has focused on detecting delamination or structural flaws in 

panel or wall paintings (Kalms and Jueptner, 2005; Morawitz 

et al., 2013). Tornari and her group at the Institute of Electronic 

Structure and Laser–FORTH spearheaded the development of 

a hybrid portable interferometry-shearography system entitled 

“MultiEncode: Multifunctional Encoding System for Assessment 

of Movable Cultural Heritage,” in which a shearography-based 

system was developed to monitor the condition of paintings 

before and after transport (Groves et al., 2007; Tornari et al., 

2009). This project also led to the development of a fringe database for using fringe patterns unique to each work as a method 

of authentication. Previous work (Georges et al., 2014) incorporating thermography, holography, and shearography has also 

indicated a multidomain approach to fault detection in complex 

multimaterial, multilayered objects with structural and mechanical complexity similar to that of paintings.

PRINCIPLES AND METHODS

The shearographic system allows for quantitative evaluation of deformations of an object and, more specifically, the 

spatial derivative, or slope, of the deformations. In general, 

the shearographic system allows for comparison between two 

or more distinct states of the object of interest, typically before 

and after application of a controlled excitation (Hung, 1982). 

The deformation of the object induces optical light path changes 

that lead to optical light phase changes in the optical setup of 

the shearographic system. Each state of the optical phase and 

intensity in the optical system, encoded within a shearographic 

interferogram, is recorded via a digital camera. By analyzing and 

comparing the phase differences between the interferograms, 

corresponding to each state of the object, the spatial gradient of 

the object’s deformation can be quantified.

Optical Setup

Our shearographic setup, shown in Figure 1, is based on 

a Michelson interferometer and works by capturing laser light 

reflected from the optically rough (Hung, 1982) surface of an 

object, which is illuminated with an expanded laser beam. Some 

of the reflected laser light passes through a lens into the shearographic interferometer, where it is split into two identical beams 

and is later recombined at the camera sensor with a slight spatial offset (optical shear) between the two beams (Huang, 1997), 

FIGURE 1. Schematic of shearography instrument and setup. The angle of a defines the measurement 

sensitivity.
number 5 • 3

as shown in Figure 1. The interference between the two beams, 

forming the original and the sheared image, gives rise to an interferogram, which consists of spatially varying intensity and phase 

patterns, also known as fringes. 

Measurements of Displacement Gradient

through Optical Phase

The specific interference pattern at each moment in time is 

a result of multiple parameters, including the geometrical and 

optical characteristics of the environment and surfaces that the 

laser light passed through or reflected from, which means that 

the interference pattern is also dependent on the geometry of 

the object of interest. Any deformations in the object, as long 

as they alter the laser light path, will induce a corresponding 

change in the optical phase of the interference pattern at the 

camera sensor. On the basis of the optical configuration of our 

shearographic system, assuming the illumination and observation (z axis in Figure 1) directions are coaxial, the optical phase 

change DX is related to the spatial gradient of displacement 

of the object s

w

d

d along the observation direction of the system 

(Hung, 1982):

, s

w s 4

m

r

d

d DX = D (1)

where m is the optical wavelength, s and D are the direction and 

magnitude of the applied optical shear respectively, and w is 

the displacement of the object along the observation direction. 

Assuming that the observation direction of the shearographic 

system and the surface normal of the object (assuming an approximately flat object) are aligned, w

ds

d becomes proportional to 

the spatial derivative of the out-of-plane displacement of the object. Our shearographic optical setup allows for optical shear in 

vertical (x axis) and horizontal (y axis) directions as well as any 

combination of the two. This allows for individually extracting 

w

dx

d and y

w

d

d , corresponding to the vertical and horizontal spatial 

derivatives of the out-of-plane displacement of the object.

These displacement gradients partially define the full strain 

tensor S, which is composed of nine components, six shear strain 

and three tensile strain components located along the diagonal 

of the tensor, as described in the following equations(Chen, 

2014):

S ,

x

u

x

v

y

u

x

w

z

u

y

u

x

v

y

v

y

w

z

v

z

u

x

w

z

v

y

w

z

w

2

1

2

1

2

1

2

1

2

1

2

1

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

= +

+

+

+

+

+

d

c

f

c b

m c

n

m

p

m

l

R

T

S

S

S

S

S

S

SS

V

X

W

W

W

W

W

W

WW

(2)

Shearing in X and Y x

w

d 4 x

d

r

m

D

DX = (3a)

individually:

y

w

d 4 y

d

r

m

D

DX = (3b)

Measurements of Optical Phase Changes

Most camera sensors, including the one that is used in this 

setup (Pike-100B with KAI-1020 CCD sensor, AVT, Stadtroda, 

Germany), are sensitive only to the intensity, and not the phase, 

of the light. As a result, several methods have been developed for 

the retrieval of the light phase, and popular methods include fringe 

skeletonization (Osten et al., 1994), phase stepping (Creath, 1985), 

and Fourier transform–based methods (Takeda et al., 1982; Ge et 

al., 2001). Our shearographic system uses a custom-made automated phase sampling technique (Harrington et al., 2010, 2011), 

which is based on a four-step temporal phase sampling method 

(Creath, 1985). The four-phase-stepping approach is implemented 

on the basis of the need for developing a high-resolution, quantitative, and real-time measuring system. The method allows for 

quantification of the phase distribution of an interferogram by 

recording its intensity four times (at four camera frames), each 

with an incremental phase shift of 90° from the previous one. 

Each controlled phase step is achieved by a custom-made phase 

stepper (shown in Figure 1), the details of which are given later 

in this work. One set of four phase-stepped frames is related to 

the shape of the object at a particular state. The deformation of 

the object between any two states is related to the corresponding 

phase change, which is defined as follows (Chen, 2014):

( , ) ( , ) ( , )

( )( ) ( )( )

( )( ) ( )( ) tan ,

x y x y x y

I I I I I I I I

I I I I I I I I 1

1 3 2 4 2 4 1 3

1 3 2 4 2 4 1 3

l

l l l l

l l l l

DX = − X X

= − − − + − − − − − − − − = G

(4)

where I1,...,4 are the four phase-stepped shearograms in the reference state and I′

1,...,4 are the corresponding data in the deformed 

state. It can be seen that the phase change is calculated on the 

basis of only intensity information. In essence, four images are 

collected at the reference state, and four images are collected in 

the deformed state, and then this equation is calculated for every 

pixel at every time instance relative to another reference time instance. In the case of continuous measurements with thousands 

of data frames (each containing four images), the reference and 

deformed data frames may be defined arbitrarily by the user in 

order to compare the differences in the optical phase between 

two data frames, which, in turn, corresponds to the gradient of 

displacements that occurs between the two instants.

This optical phase sampling method assumes that during the 

capturing of the required four interferograms at each deformation 

state, the object and the surrounding environment are steady and 

do not induce a significant phase change on their own. The adequacy of this assumption has been verified through pilot tests in 

the museum environment based on the test setup described later in 

this chapter, as well as based on the literature (Kalms and Jueptner, 

2005; Morawitz et al., 2013). This optical phase sampling method 

was chosen because of its superior spatial resolution, allowing for 

a quantification of the phase sampling at each pixel individually. 

The specific choice of the number of phase shifts and phase step 

size was defined on the basis of pilot studies of shearographic measurements on oil-on-canvas paintings in our laboratory settings 
4 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

(Chen et al., 2014; Khaleghi et al., 2014) as well as literature 

(Kalms and Jueptner, 2005; Morawitz et al., 2013). Further work 

might be needed to find an optimal phase sampling technique and 

corresponding acquisition parameters; however, the ones used in 

this work were deemed sufficient for our preliminary work.

Temporal Unwrapping of Optical Phase Changes

Because of the use of the arctangent function in equation (4) to calculate phase differences, the resulting phase data 

“wraps” within a range of –r to r radians, which causes spatial 

discontinuities in the spatial distribution of the measured phase 

across the recorded image. This wrapping of data is particularly 

challenging when measuring displacements that occur over an 

extended period, and as the displacement gradient increases, 

repeated wrapping occurs, and the resulting image becomes increasingly difficult to interpret. It is therefore necessary to demodulate or “unwrap” the data. 

Existing spatial phase unwrapping algorithms have limited 

capabilities in the analysis of interferometric images of objects 

undergoing physical deformations that result in a large number 

of phase discontinuities (>50 cycles of phase across the field of 

view). The temporal phase unwrapping algorithms developed in 

this research and on the basis of existing methods (Huntley and 

Saldner, 1993) overcome this limitation. The basic idea behind 

the method is that the phase change at each pixel is measured as 

a function of time and is unwrapped along the temporal dimension independently of the neighboring pixels (Dobrev et al., 2012; 

Kreis, 2005). The temporal unwrapping method (Chen, 2014) 

relies on the assumption that the phase change between any two 

consecutive frames is between −r and +r. This is an adequate assumption for this application because although the object may be 

undergoing large deformations, the temporal rate of the deformations is relatively slow. Typical significant changes for the range 

of our shearographic system and setup take >1 s to develop under 

typical testing conditions in museum settings, whereas the camera 

recording is done at 60 frames/s, resulting in <70 ms to capture a 

set of four images. The effects of random noise, which might contribute to significant phase variations between frames, has been 

suppressed with the use of spatial averaging filters with a size (i.e., 

3 × 3 pixels) adjusted on the basis of the smallest features (i.e., 

<1 mm) that were considered to be important for this research. 

Although surface cracks could be much smaller, we assumed that 

their effect on the local deformation patterns will be sufficiently 

large in space to be detected by the shearographic system. Additionally, because of the inherited scalability of the optical system, 

analyzing a smaller region with a greater level of spatial detail 

and sensitivity is just a matter of adjusting the zoom lens or the 

shear, without any change in the overall analysis procedure. 

Calibration of the Measurement Sensitivity

An important point to make from equation (1) is that the 

sensitivity of the system is highly affected by the amount of shear. 

Therefore, it is important to quantify the shear amount in order 

to convert the phase data from radians to appropriate engineering units.

This research implements a method based on the shift theorem of the Fourier transform that allows for the direct estimation 

of the shear amount without any pre- or postcalibration procedures (Figure 2). The technique is based on existing computer 

vision methods used to estimate camera motion during television 

broadcast (Bracewell et al., 1993; Licsár et al., 2003). The idea 

behind this method is that the 2D fast Fourier transform (FFT) of 

the superposition of an image and its sheared twin (i.e., the case 

of shearograms) will result in a 2D power spectrum, the magnitude of which is sinusoidally modulated with a period inversely 

proportional to the shear amount (Khaleghi et al., 2014). Typically, the images are captured individually and superimposed 

digitally, although in the case of shearograms, the two images 

are superimposed optically and are captured simultaneously, but 

this does not change the general principle of the method. For 

FIGURE 2. Illustration of the mathematical principle behind the automatic shear estimation algorithm. A power spectrum of 

the 2D FFT of a shearogram: (a) with no shear, (b) with shear in the horizontal (x) direction, and (c) with shear in the horizontal (y) direction. The corresponding modulation period is indicated (Chen, 2014).
number 5 • 5

example, for a horizontal shear (i.e., along the x direction), the 

relation between the period Tx

 of the modulation in the 2D FFT 

power spectrum (Figure 2b) and the shear amount x0 can be expressed as (Chen, 2014)

x x , T

N

x 0 . D (5)

where Dx and N are the pixel size and number of pixels in the 

shear direction, respectively. By automatically extracting the period of the modulation in the FFT of the shearogram, we get the 

shear amount in the system. A novelty of our work (Khalegi et 

al., 2014; Dobrev et al., 2012; Chen, 2014) is in the development 

of automatic software for shear estimation and its application 

for shearography analysis. This tool greatly simplifies and accelerates the measurement procedures, as it does not require any 

calibration after each adjsutment of the shearographic system, 

thus allowing for rapid optimization of the recording parameters 

relative to the response of each new sample or loading procedure.

TEST SETUP

Initial tests in this research used shearography to see if a 

thermomechanical response could be detected on the surface of 

an oil painting as a result of simply turning on and off lights such 

as those used in a typical photography session. The setup mimicked the same configuration used at the time by the museum 

conservators for photographing works, the only difference being 

that the camera was replaced with the shearography instrument 

and workstation (Figure 3).

The shearography instrument constructed at Worcester 

Polytechnic Institute (WPI) is a mobile system that utilizes an 

adjustable tripod, a computer workstation, and an uninterrupted 

power supply (UPS) to power the system between relocations. In 

this case, the coherent light source is a 473-nm laser (50 mW, 

Diode-pumped solid-state [DPSS], Oxxius, Lannion, France), 

and the measuring head consists of a custom-built interferometer, a camera lens (zoom lens, 12.5–75 mm, model 53-153, Edmund Optics, Barrington, New Jersey, USA, and a camera (Pike 

F100B, AVT) interfaced directly to the computer workstation 

(Figure 3). The measuring head has an approximate size of 25 × 

25 × 25 cm, excluding the lens and the IR camera, which can be 

easily removed or changed in accordance with the needs of each 

experiment. The size of the shearographic optical head, excluding the lens, laser, and IR camera, is 25 × 7 × 7 cm. The laser was 

mounted directly next to the lens, aligned approximately (i.e., 

<2° deviation) parallel to its optical axis. The laser beam, with a 

diameter of <0.3 mm, was expanded to a circular spot with a diameter of ~40 cm. The camera consists of a Truesense KAI-1020 

CCD sensor, which has a resolution of 1,000 × 1,000 pixels at 

FIGURE 3. Schematic of the shearography setup during initial tests.
6 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

7.4-μm pixel pitch. The camera exposure time was 10 ms, with 

a frame rate of 60 frames/s. Phase shifting was achieved through 

a custom-made phase stepper based on a customized piezoelectric transducer (PZT; PAS005, Thorlabs, Newton, New Jersey, 

USA), driven by an analog output card (DAQ, NI USB-6343, 

National Instruments, Austin, Texas, USA) via a piezo controller 

(MDT694B, Thorlabs). All of the above components were combined into a compact optical head, shown in Figure 3.

Connectivity in the instrument includes firewire B from 

camera to laptop, USB 2.0 from DAQ to laptop, and Bayonet 

Neill-Concelman (BNC) cables from DAQ to PZT amplifier and 

camera (the camera triggers the DAQ, which then steps the PZT). 

The instrument is also equipped with an IR camera (FLIR A310) 

connected via GigE to the laptop in order to correlate thermal 

data with the shearography data. Excluding the IR camera, the 

instrument costs a few thousand dollars, the most expensive 

component being the camera. The control software was custom written at WPI (Harrington et al., 2011) and allows for the 

automatic continuous synchronization between camera frames 

and phase stepping, full control of all system settings (exposure, 

frame rate, recording speed, etc.), and storage of data and live 

display of the current phase map referenced to any desired frame.

A 473-nm, 50-mW laser was used essentially because it was 

the least powerful of the lasers available in the lab at the time in 

order to minimize the thermal excitation of the painting while 

providing sufficient illumination of the area of interest to allow 

shorter camera exposure times and higher recording speeds. The 

laser’s coherence length is >10 m; however, a long-coherence 

laser is not necessary, and previous research (Falldorf et al., 

2003) has shown the possible use of a white light source with 

limited coherence length (i.e., temporal coherence of <50 nm). 

One of the main constraints for use of a short-coherence light 

source is the maximum observable gradient of the object’s surface, which is dependent on the applied shear and the direction 

of illumination (Falldorf et al., 2003). Tests with laser diodes 

from pointers, with a coherence length of <0.5 mm and a cost of 

<$10, indicate that sufficient amounts of shear can be achieved 

for quantitative analysis of flat objects (Chen, 2014), similar to 

pictures. Although this assumption may not hold at the steep 

walls of cracks on the paint surface, we assume that the cracks 

will influence the deformation of flat areas in their proximity, 

which in turn will be sufficient to estimate the location of the 

cracks within the spatial resolution of the system (i.e., <0.5 mm).

The initial setup (Kaleghi, et al. 2014) (Figure 4) positioned 

the system 1.8 m from the painting analyzed, allowing for the 

full field of view (FOV) range available with the objective lens. 

However, because of power limitations of the laser, the FOV was 

kept to 0.35 m, leaving the spatial resolution of the measurements to be 0.15 mm/pixel. The loading source in these initial 

tests was two Lowel Tota-lights with 500-W halogen bulbs, each 

equipped with a diffusing umbrella and positioned at 45° angles 

2.3 m from the painting. The spectrum of the lights covers nearly 

the full visible range, including the laser’s 473 nm, as well as a 

sufficient amount of infrared radiation for thermal excitation of 

the sample. The initial testing consisted of a 60-s loading period with the lights on, then a 60-s recording time immediately 

after turning the lights off (unloading period), which resulted in 

a 0.7°C increase in surface temperature of the painting in the 

loading cycle. Because of the high power of the lights compared 

to the laser, the shearographic system’s camera saturated during 

the loading cycle. As a result, only the unloading period (lights 

off) was shearographically recorded. 

The painting used throughout this research was an unlined, 

late nineteenth-century oil on canvas that is privately owned. The 

paint surface exhibits a network of craquelure and, to a lesser extent, drying cracks throughout, a few scattered paint losses, and 

a small puncture. The paint thickness varies from thin to areas 

with moderate impasto. 

Previous work combining shearography and thermography has indicated the potential advantages of IR cameras in 

FIGURE 4. The CAD model of the instrument (left) and the realized instrument (right). (Chen, 2014; Chen et al., 2014)
number 5 • 7

shearographic inspection (Georges et al., 2014). The integrated 

IR camera enabled researchers to map the surface temperature of 

the painting throughout the process. The temperatures across the 

full surface of the painting, the frame, and the background wall 

were recorded. The temperature uniformity across the paint surface was within 0.2°C, and the average temperature change was 

within 0.3°C–0.6°C, with smaller changes at the periphery and 

larger changes at the center of the picture. The spatially varying 

temperature changes can be explained by better heat dissipation 

at the edge of the painting surface because of its proximity to the 

frame and stretcher structure. A 6-min equilibration period took 

place in between loading-unloading cycles, enabling researchers 

to start from the same temperature during each run. 

CONTROLLED TEMPERATURE 

EXCITATION TESTING

Since the shearography system allows for recording with 

one shear direction at a time, at least two recordings are needed 

to capture the X (horizontal) and Y (vertical) components of the 

spatial gradient of the out-of-plane deformation individually. We 

verified the reliability of such a method by performing at least 

three measurements, each following the procedure described in 

the previous section, in each shear direction, which indicated a 

standard deviation of <5% of the maximum detected slope of 

deformation. The X and Y data sets were then combined to create a cumulative gradient of displacement map with a magnitude 

converted into microstrains, the unit preferred for representing 

such data (bottom row in Figure 5). The reference for all measurements, at each thermal cycle, was the first measurement (four 

phase-stepped frames) immediately after turning off the lights. 

Data in the bottom panels in Figure 5 refer to an example measurement made 10 s after turning off the lights. The data appear 

to indicate displacements that correspond to a dense crack network. Note the relatively large displacement gradients along the 

top and right margins roughly corresponding to the underlying 

stretcher bar support. 

The 10-s time mark, indicated in Figure 5, roughly corresponds to the maximum spatial density of contours (fringes) of 

the wrapped phase (Figure 5, top middle panel) that could be still 

unwrapped via conventional spatial phase unwrappers (Ghiglia 

FIGURE 5. Analysis of an oil painting on canvas showing the transient response to thermal loading. An image 

of the upper right quadrant of the painting that was analyzed (top left) and the corresponding maps of wrapped 

and unwrapped optical phase measurements taken during a 10-s period of cooling immediately after turning 

the lights off (top middle and right). Color-coded gradient of displacement maps in the X and Y shear directions (bottom left and middle, respectively) and the absolute value of the combined gradients of displacement of 

both X and Y data sets with the scale in microstrains (bottom right). Painting analyzed: Untitled, oil on canvas, 

unknown artist, private collection.
8 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

and Pritt, 1998). However, since the response of the painting 

reached a relatively stable state only after 1 min, recordings were 

done for 60 s, at which point the spatial density of the wrapped 

phase contours becomes too high. Thus, only the temporal phase 

unwrapping algorithm was used for all recordings in this paper. 

The first 10 s have been presented as an illustration of the analysis approach, and a detailed analysis of the full 60-s cooling cycle 

will be included in a future work.

Temporal variations of the derived gradients of displacement can be viewed relative to each other in Figure 6. The ability to correlate strain to the temporal domain can be used not 

only to chart thermomechanical response but also to inform our 

understanding of equilibration properties of the object analyzed 

(Figure 6). This could be achieved by combining the full-field 

displacement gradient measurements with the full-field temperature data from the IR camera in order to obtain intrinsic material 

properties such as local heat coefficients and thermal time constants, which can be used to optimize the preservation conditions 

for each picture individually.

In order to provide more detailed information for the deformation pattern and cracks, we combined the magnitude and direction information of the combined data for both the X and Y

deformation gradients into a single display, as show shown in Figure 7 (right), where corresponding color-coded arrows indicate the 

direction and magnitude of deformation gradients. It should be 

noted that although the vectors are expressed in plane, since they 

show the spatial direction of the highest slope of deformation, the 

deformations and the corresponding strains are occurring out of 

plane. Superposition of the resultant strain map on a ghost image 

of the area analyzed can help correlate gradients of displacement 

information with features present on the paint surface or under it. 

IN SITU GALLERY TESTS

Following the tests that mimicked the Worcester Art Museum’s lab photography setup, investigations shifted into the 

Worcester Art Museum galleries. On a two-day span in July, 

when the museum was closed to the public, a small painting on 

exhibit was replaced with the test painting, and the shearography 

instrumentation was set up in the gallery to monitor changes that 

occur over the course of a typical day-night cycle. In this case, 

the light loading was provided by broad washes of light from 

a pair of ceiling-mounted 50-W halogen bulbs 4 m away. For 

comparison, the same region of the test painting was analyzed. 

The combination of lower-power lights and the larger distance 

from the painting resulted in greatly reduced negative effects of 

the museum lighting to the shearographic system, such as local 

saturation and reduced fringe contrast, and allowed continuous 

operation regardless of the state of the lights. Preliminary noise 

floors tests of the shearography system under such conditions 

indicated ~m/15 phase variation, equivalent to ~8 nf.

FIGURE 6. Gradient of displacement maps over a 10-s period of cooling when shear is in the Y direction (top row) and in the X direction 

(middle) and the resultant gradient of displacement maps when both shear directions are combined (bottom).
number 5 • 9

Setting appropriate acquisition parameters was a critical step, 

particularly regarding frame rate in order not to overwhelm the 

computer’s memory capacity and the analyst’s capacity to process 

the data. Data were taken in a time-lapse manner by making one 

measurement, consisting of four phase-stepped frames taken in a 

burst at 60 frames/s, every 10 s for a total duration of 27 hours, 

resulting in ~10,000 measurements (i.e., ~100 GB). 

Temperature and relative humidity (%RH) data for the 

gallery were recorded internally in the museum’s HVAC system throughout the course of the investigation and varied from 

46.8% to 49.8% RH and from 23.1°C to 24.4°C. The recorded 

temperature and %RH timeline was also used to plot significant 

events, such as the beginning and ending of shearography analysis and when the lights were turned on or off (Figure 8, top). 

Shearography data were later analyzed to see if correlations exist 

between changes in gallery conditions and strain responses in the 

paint surface.

The amount of data acquired with the shearography instrument is substantial and presents a challenge for postprocessing. 

Ongoing work with processing software seeks to assist with this 

process. Efforts thus far have focused on examining data for correlations between detectable strain and changes in gallery lighting. Data revealed that even in the tightly controlled climate of 

the gallery, the paint surface underwent a detectable thermomechanical response when the lights were turned on or off (Figure 

8, bottom row). 

The maps in Figure 8 show that the greatest (i.e., 100–

120 nf range) strain incurred shortly after turning on the lights 

is along the edge of the canvas, whereas the center appears relatively stable. The reverse is true when turning off the lights. The 

low (i.e., 20 nf) level of strain detectable (noise floor is <10 nf) 

during the stable state, represented here by Figure 8a, is likely related to ambient vibration. As the analysis progressed, it became 

increasingly apparent that the sensitivity of the shearography instrument enables clear correlations to be drawn between exhibition conditions and physical changes in the painting. 

Future work on this experiment will involve application of 

the temporal unwrapping software in a memory efficient way on 

the full data set. Once this is complete, the next step could be the 

comparison between the full shearographic data and the climate 

control parameters in order to analyze the response of the picture. Such a comparison could help us devise a scheme for the 

optimization of the climate control parameters to minimize strain 

fatigue on the painting while minimizing energy consumption.

CORRELATING SHEAROGRAPHY DATA 

TO TOPOGRAPHICAL FEATURES

The final component of this investigation explored how to 

improve capabilities for correlating shearography data with existing topographical features on the surface of paintings. This 

general problem is noted in the literature and was encountered 

firsthand when trying to relate shearography data to the network of cracks evident on the test painting. The images shown 

in Figure 8 of gradients of displacement and strain vector maps 

illustrate how processed shearography data can be overlaid with 

conventional camera images of the corresponding area. However, 

because of the lack of quantitative information about the topological features captured in conventional camera images, the encoded color information about the paintings surface may not be 

representative of the painting’s surface topology and underlying 

FIGURE 7. Representative in-plane laser shearography measurements of the upper right region of the painting analyzed (left). Color-coded 

strain map of same area indicating gradients of displacement originating along discontinuities in the paint film during a 10-s cooling period 

directly after thermal loading with photography lights (middle). The corresponding strain vector map indicating magnitude and direction of 

induced strain via color-coded arrows (right). Painting analyzed: Untitled, oil on canvas, unknown artist, private collection.
1 0 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

structure. The discrepancy between color information and surface topography makes a direct comparison with shearographic 

data more difficult to interpret.

In order to facilitate comparison with a greater level of detail, we utilized the visually rich surface imaging technique of 

reflectance transformation imaging (RTI), and we explored it as 

a possible compliment to shearography data. Because of limitations with the FOV of the available RTI system (lighting array 

system designed by the Cultural Heritage Imaging Corp., San 

Francisco, California, USA), only about 50% of the area, as 

shown in the previous two experiments, was available for comparison with the shearographic system. For direct side-by-side 

comparison with the gradient of displacement maps, the specular 

enhancement viewing function available in RTI viewing software 

(RTIViewer V1.1, Cultural Heritage Imaging Corp.) was initially 

considered, as it enhances the visible details of the topography of 

the paint surface (Figure 9, middle). However, in order to remove 

any subjectivity in relating gradients of displacement to physical 

features on the painting, other approaches were considered. The 

improved functionality of the most recent RTI viewing software 

allows one to generate per-pixel surface normal data, which 

quantifies the in-plane and out-of-plane slope of the shape of the 

painted surface. The surface normal is related to the slope of the 

surface shape and therefore can be interpreted as a collection of 

two pieces of information: the magnitude and the direction of the 

slope of the local shape. A slope with larger magnitude indicates 

steeper surface features such as those at the crack boundaries 

and walls. For this reason, magnitude information was extracted 

from the surface normal data and further color coded such that 

deep blue or red indicates high positive or negative slope and 

green indicates no or very little slope of the surface topography 

(Figure 9, right). 

Our main hypothesis behind such an approach is that surface cracks, detectable through the RTI surface normal data, will 

FIGURE 8. Temporal variation of the %RH and temperature over a 48-hour span (top). Arrows indicate start and stop times of shearography 

analysis, as well as times when lights were turned on or off. Three strain maps of the same upper right area of the test painting taken at different 

times: (a) 10 s before turning on the gallery lights, (b) 10 s after turning on the lights, and (c) 10 s after turning off the lights.
number 5 • 1 1

produce a significant strain pattern in their close vicinity, which 

will be detectable with our shearography system. On the other 

hand, cracks close to the surface, but without visual indication 

via the RTI system, will also produce a significant strain pattern 

in their vicinity, which would affect the surface strain pattern and 

in turn would also be detectable by the shearographic system.

The first part of this hypothesis is supported by an example 

of details shown in Figure 10, where there is a clear correspondence between the strong gradient of displacement present and 

the presence of a high spatial slope indicative of a crack. On 

the other hand, the second part of our hypothesis is supported 

by other details analyzed, which showed areas with little to no 

correlation between shear and RTI data, possibly because of the 

presence of subsurface discontinuities that are not related to surface topographical features. To our knowledge, this may well 

be the most exacting correlation between topography and loadinduced strain done for the surface of a canvas painting to date. 

This approach not only could locate damage or imperfections 

in the layered structure, providing insight into the time-based 

thermodynamics of painted surfaces by mapping the actual magnitude and direction of displacements, but also it could allow for 

correlation of such findings with physical features visible on the 

paint surface. This blend of different quantitative data analyses 

from different domains could be an effective predictor of where 

strain-induced damage such as crack propagation is likely to 

occur in paint surfaces. Future work will incorporate more rigorous comparison between shearographic and RTI data based 

on visible and subsurface paint defects. Additionally, work will 

be expanded via correlation with other domains, such as X-ray 

and optical coherence tomography (OCT), to further confirm the 

effectiveness of the blend of RTI and shearography data and to 

establish better testing methods and detection procedures.

CONCLUSIONS

The shearography system developed at WPI provides researchers with the ability to quantify and map induced strain 

using gradients of displacement. Directional vectors of these gradients of displacement can also be mapped in order to better understand the response of painted surfaces to different loadings. 

Temporal unwrapping algorithms of displacement gradients enable researchers to directly correlate displacement response to 

events in time. Furthermore, a complementary approach using 

shearography and RTI provides a more exacting degree of correlation between displacement gradients and surface topography.

Ultimately, the aim is to combine future work involving material fatigue and failure thresholds with multidomain 

FIGURE 9. Side-by-side comparison of a shearography-generated gradient of displacement map with ghost overlay (left) and RTI-generated 

views of the same paint surface as seen with specular enhancement (middle) and as a contrast-enhanced surface normal map (right). A comparison between the RTI and shearographic (abbreviated as “shear”) data is shown in Figure 10. A direct pixel-to-pixel comparison required spatial 

transformation of the RTI data and scaling of both data sets. Although the RTI data offered 80 times more spatial information (80 megapixels 

versus 1 megapixel in our shearographic setup), it was reduced and spatially transformed in order to facilitate direct comparison with shearographic data. This reduction was also done in order to focus on spatially larger and potentially more significant features. The reduction was done 

through affine transformations of the RTI data to the shearographic data set while using linear interpolation to spatially resize and compress 

the RTI image. The affine transformation was defined through manual selection of similar spatial points in both image sets. Additionally, for 

comparison with the RTI data, the absolute of the combined strain data was used in order to enhance regions of large positive or negative strain 

(both indicated with red in Figure 10), indicative of cracks. Since two data sets are coming from two different domains with different engineering units, we normalized each cross section to a range of 0 to 1 to facilitate comparison. After these manipulations, small details of the painting 

surface were used to generate and plot cross-section data of the RTI and shearographic data for comparison (graph in Figure 10).
1 2 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

shearography-based measurements in order to make fully informed recommendations on how to optimize a sustainable approach for climate control standards in museums. 

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ABSTRACT. Two paintings made by the same artist in 1616 to depict The Dinner and The Dance 

celebrations of the Pipenpoyse Wedding were examined at Stichting Restauratie Atelier Limburg, 

Maastricht, Netherlands. In addition to a shared provenance these paintings demonstrated similarities in their composition and identical materials and techniques. However, the paintings exhibited 

dramatic differences in their condition, and inconsistencies between their previous treatments were 

apparent. One of the paintings, The Dinner, had undergone repeated surface treatments of varnishing and varnish removal, whereas the other, The Dance, had never been varnished. The paintings 

thus presented an opportunity to potentially examine the accumulative effects of paint surface treatments using organic solvents. Detailed depth profiles of the two paintings were measured using 

single-sided nuclear magnetic resonance (NMR). This type of NMR is sensitive to physical properties of the material such as hardness and is a contact-free technique. The T2

 relaxation times, 

indicative of the hardness or stiffness of a material, were found to be different for the two paintings 

and consistent with the observed visual and tactile differences. With regard to these findings the 

contribution from the repeated exposures to natural resins and organic solvents during paint surface treatments is considered. Various developments in current conservation practice have aimed to 

restrict the penetration of solvent into paint films and thereby reduce related solvent effects. Initial 

findings from investigations using single-sided NMR on model paint films to compare the effects of 

such adapted approaches are presented.

INTRODUCTION

Varnishing and varnish removal are the most common treatments applied to the 

overall surface of oil paintings involving organic solvents. Various methods and analytical techniques have been previously employed to investigate the effects of organic 

solvents on oil paint films (Stout, 1936; Jones, 1965; Maschelein-Kleiner and Deneyer, 

1981; Stolow, 1985; Erhardt and Tsang, 1990; Hedley et al., 1990; Michalski, 1990; 

1

 Stichting Restauratie Atelier Limburg, Avenue Ceramique 224, 6221 KX Maastricht, 

Netherlands.

2

 RWTH Aachen University, Institute of Technical 

and Macromolecular Chemistry, Worringerweg 1, 

52062 Aachen, Germany.

3

 The College of William & Mary, Department of 

Chemistry, 540 Landrum Dr., Williamsburg, Virginia 23185, USA.

* Correspondence: G. Fife, gwenfife26@hotmail

.com

Manuscript received 27 May 2014; accepted 22 

February 2016.

Evidence for the Accumulative Effect 

of Organic Solvent Treatments on Paintings 

and What to Do about It: A Case Study 

of Two “Identical” Seventeenth-Century 

Paintings Using Single-Sided Nuclear 

Magnetic Resonance

Gwendoline Fife,1* Bascha Stabik,1 Bernhard Blümich,2

Renè Hoppenbrouwers,1

 and Tyler Meldrum3
1 6 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

Tsang and Erhardt, 1992; Phenix, 1998; Tumosa et al., 1999; 

Phenix and Sutherland, 2001; Sutherland, 2001; Phenix, 2002a, 

2002b; Fuesers and Zumbühl, 2008; Zumbühl et al., 2010; 

Zumbühl, 2014).1

 Their results have been highly beneficial to 

our field in developing our conceptual modeling and understanding of paint films and the potential negative effects from 

solvents. From a practitioner’s perspective, examining how the 

magnitude of these “invisible” solvent effects can be influenced 

by our techniques and practices is a pertinent focus, and this 

paper shall describe the novel application of single-sided nuclear 

magnetic resonance (NMR) in this endeavor. A case study of 

two “identical” seventeenth-century paintings examined with 

single-sided NMR and experiments on a simple painting model 

will be discussed.

Analytical Methods

In an NMR experiment, a sample is placed in a large, homogeneous magnetic field, and the response to that field is measured, producing a spectrum. Interpretation of that spectrum 

reveals the structure of the molecule of interest. Although chemical identification of compounds is tremendously powerful, the 

technique is not an analytical panacea. One particularly pertinent 

drawback is the size of the sample—most magnets accommodate 

samples only millimeters across, not entire paintings. Reducing 

an NMR apparatus to its simplest components, one needs just 

three things: a sample, a magnet, and a radio-frequency coil (an 

antenna). If two or more permanent magnets are cleverly arranged next to each other, the field between them can be made 

fairly flat and homogeneous in a region above the magnets themselves. This offset of the magnets and their magnetic field allows 

for an unconventional geometry of an NMR experiment—one 

in which the sample sits atop, rather than within, the device. 

Using these single-sided magnets, samples of arbitrary geometry 

can be analyzed to probe certain physical properties of a material. The field homogeneity is, however, not good enough to give 

chemical information: chemical shifts, the most common way to 

identify functional groups in and the structure of molecules using 

NMR, are inaccessible with single-sided magnets. Single-sided 

NMR can access information about the relaxation rates of nuclear magnetization following the application of radio-frequency 

radiation; these relaxation rates indicate physical properties of 

the system. 

The relaxometric data that single-sided NMR experiments 

generate comprise signals that decay with time. From that decay, 

one can extract two significant parameters: the signal amplitude 

and the rate of signal decay. The signal amplitude, designated 

A, indicates the quantity of proton-containing material in the 

measured location, whereas the rate of signal decay, evaluated 

by the NMR parameter T2

, indicates the strength of the intermolecular network. In samples with a small value of T2

 (rapid 

signal decay), there is a strong intermolecular network, often 

associated with a stiff or brittle material. A large T2

 (slow signal 

decay) may suggest a softer material (Bloembergen et al., 1948). 

Thus, depth profiles with T2

 and A show the strength of the intermolecular network at different positions within the thickness 

of a painting.2

The sensitive region of the single-sided magnet used in these 

studies (Blümich et al., 1998) has an area of approximately 6.25 

cm2

 and an adjustable thickness of between 10 and 500 μm for 

a sample volume of up to 0.3 mL. In addition, it is positioned 

between 1 and 5 mm above the surface of the magnet. If one 

suspends a sample just above the magnet but below the sensitive region and makes repeated measurements while moving the 

magnet down, a signal profile can be generated as a function of 

the depth through the sample.

EXPERIMENTAL OVERVIEW

Varnish removal may be undertaken for a number of reasons, 

including conservation of the original materials (e.g., by allowing 

better consolidation), improvement of the painting aesthetically, 

or enabling a more accurate and sensitive restoration campaign 

using stable materials. Varnish layers may be (re)applied for saturation, isolation of original materials from subsequent restoration, 

or protection of the paint surface. Given the potential side effects 

from solvents (e.g., swelling, loss, or movement of low-molecularweight components) such treatments involve risk assessment. 

Since the conscientious conservator will aim to minimize any 

potential risks to an acceptable level before varnish removal is 

undertaken, any observable changes to original materials during 

treatment are unacceptable. Concern instead lies with the risk of 

engendering subtle long-term effects, invisible at the point of treatment yet indicated by previous research (Maschelein-Kleiner and 

Deneyer, 1981; Stolow, 1985; Erhardt and Tsang, 1990; Hedley 

et al., 1990; Michalski, 1990; Tsang and Erhardt, 1992; Phenix, 

1998; Tumosa et al., 1999; Phenix and Sutherland, 2001; Sutherland, 2001; Phenix, 2002a, 2002b; Fuesers and Zumbühl, 2008; 

Zumbühl et al., 2010; Zumbühl, 2014) and, from our experience, 

observable when examining previously treated paintings. However, given the individuality of each painting, the complexity of 

its structure, and the number of unknowns in its lifetime, it is not 

possible to quantitatively correlate these specific aspects of treatment history with current condition.

For measuring the effects of previous treatment, the real-life 

equivalent of an experimental “control” would be ideal. Such a 

control could comprise two paintings made a long time ago by 

the same artist with the same materials and techniques and at 

same the time, with the only difference being only one had never 

undergone organic solvent–based treatments (varnish application 

and removals). Extraordinarily, in 2011 two paintings arrived 

at Stichting Restauratie Atelier Limburg (SRAL)—as part of a 

larger treatment project from the Fries Museum in Leeuwarden, 

Netherlands—displaying exactly these characteristics. Called 

The Dinner (212 × 124 cm) and The Dance (218 × 130 cm; 

from the Pipenpoyse Wedding set), the paintings were attributed 

to the same artist, were very similar compositionally (Figure 1), 
number 5 • 1 7

FIGURE 1. (top) The Dance (218 × 130 cm) and (bottom) The Dinner (212 × 124 cm) from the Pipenpoyse Wedding Set (1616), 

artist unknown. The surface of The Dance has never been varnished or otherwise treated with organic solvents. In contrast, The Dinner has undergone numerous solvent-based varnish removals. For legibility of the images, paintings are shown here after SRAL treatments. Paintings: Fries Museum, Leeuwarden, Netherlands. Photographs courtesy of Stichting Restauratie Atelier Limburg (SRAL).
1 8 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

had very similar dimensions, and were both dated 1616. As part 

of an originally larger series they were known to have hung together in the big hall in the Liauckamastate in Friesland until 

the estate was demolished in 1824, after which they remained in 

the family collection until going in 1963 to the Fries Museum. 

No further information regarding the specific environments experienced by the two paintings is known, nor is there any existing documentation regarding previous treatments. Apart from 

local tear repairs in The Dinner, the only structural treatments 

for both paintings involved restretching: two for The Dance and 

three for The Dinner. Regarding surface treatments, The Dinner was varnished with natural resins and cleaned (although 

unevenly) at least twice, and there were numerous overpaints 

visible above the first varnish layer. With The Dance, there were 

no indications that its surface had ever been varnished or otherwise treated with organic solvents. 

Various visual, material, and technical examinations were 

carried out on these paintings, and they constitute the first set of 

experimental materials with the single-sided NMR that will be 

discussed here. For NMR measurements, each individual painting was positioned on an easel in its normal vertical position, 

and identical data acquisition parameters were used for measuring both paintings.3

 With the magnet mounted on a lift to control 

horizontal positioning it was placed parallel to and as close as 

possible to the surface of each painting in turn.

The second sample set consists of 2.5 × 2.5 cm sections cut 

from a very simple, unvarnished, and uniform painting model 

consisting solely of a single red oil paint layer (containing lead 

white, chalk, and red ochre) on sized linen canvas, naturally 

aged for around 10 years. Since in normal working practice only 

a low level of invisible solvent effects can be anticipated during 

an individual varnish removal (Phenix and Sutherland, 2001), 

these model samples were subjected to deliberately extreme solvent exposures to allow a comparative examination of resulting solvent movement and the potential solvent effects induced 

by different varnish removal techniques. Although not typically 

employed for varnish application or removal, 1-methoxy-2-

propanol was selected for these tests precisely because it caused 

a slow (and initially optically invisible) but ultimately high 

swelling of the model paint layer with a significant period prior 

to dissolution. 

The two techniques selected for comparison were application of free solvent in a swab—hereafter referred to as free 

solvent—and a version of SRAL’s tissue gel composite method 

(Fife et al., 2010, 2011). With this latter technique—hereafter 

referred to as thickened solvent—the thickened solvent (3% w/v 

using hydroxypropyl cellulose) was applied in a tissue, with a 

secondary absorbent tissue step. Pretesting was carried out, and 

a desirable time exposure of 30 seconds was determined for the 

application of both techniques. NMR and gravimetric measurements were carried out both immediately before and after each 

technique application (Fife, 2015). During NMR testing, samples 

were placed between two microscope slides to maintain correct 

position and avoid solvent loss during measurement.

4

RESULTS AND DISCUSSION: SET 1

Each painting comprised two canvas pieces with a central 

seam. In The Dinner all sides had been cut, and the painting had 

been made smaller. In The Dance, since there was one painted 

turnover edge with original threading holes, a loom size of 

110 cm could be calculated. The canvas support of The Dance

was highly flexible and light in color, indicating less oxidation of 

fibers. No resin residues were observable in normal and ultraviolet light examinations. In contrast, the canvas of The Dinner

was embrittled, and evidence of resin appeared throughout the 

structure, with residues observable (in accordance with surface 

crack pattern) on the canvas reverse. 

Aside from surface dirt and mechanical damage caused by 

previous folding, the paint and ground layers in The Dance had 

an excellent condition overall. There was also a noticeable lack of 

cracking on the paint surface (Figure 2). In contrast, The Dinner

showed typical “age” cracks in the paint film across the surface. 

It appeared more brittle and was also more glossy and saturated. 

Infrared reflectography indicated no technical differences in 

the preparatory underdrawing of the paintings. Twelve samples 

were removed from comparable areas of each painting for further examination in cross section with visible and ultraviolet 

light microscopy, with staining tests.5

 X-ray fluorescence of both 

paintings surfaces (at 26 spots) was further carried out.6

 The 

combined findings from these analyses confirmed an identical 

painting technique and pigment palette (lead white, vermilion, 

red lead, earth pigments, carbon black, and calcium carbonate 

in ground) with the same layer buildup and oil binder. A comparable area in both paintings, a red flower on the background 

wallpaper, was selected for NMR measurements. A sample from 

each painting was subsequently removed from this same area to 

quantify the individual layer thicknesses for correlation with the 

NMR-generated profiles.7 Optical microscopy gave comparable 

paint plus ground layer depth measurements, and elemental 

mapping using energy-dispersive x-ray spectroscopy (EDX) verified identical pigment compositions (Fife and Meldrum, 2014). 

Scanning electron microscopy (SEM) indicated some condition 

differences: the paint and ground layers in The Dinner sample 

showed cracks, fissures, and pores, and the layers appeared less 

discrete (Figure 3).

Single-sided NMR measurements, carried out in the nominated 2.5 × 2.5 cm area in both paintings, were taken at 15-μm 

increments throughout the thickness of each painting. The results are shown in Figure 4 and include both signal intensity A

(top) and T2

 (bottom).8 In The Dance the signal intensity was 

somewhat variable across the painting, with a gradient of increasing T2

 values toward the rear of the painting. In The Dinner the signal amplitude was larger but similarly variable as in 

The Dance.

9

 The T2 value in The Dinner was small and constant 

throughout 600 μm below the painting surface and increased 

dramatically at the back of the canvas. 

The Dance’s paint was stiffest at the surface of the paint 

film with then a smooth gradient of decreasing stiffness through 
number 5 • 1 9

depth of ground, whereas The Dinner is uniformly stiff, as stiff 

as the uppermost surface of The Dance, throughout almost its 

entire depth. 

Studies of oil paint films have shown that after initial drying, oxidation reactions continue in the polymeric oil network 

whereby lower-molecular-weight (LMW) components can be 

formed. These LMW components (e.g., free fatty acids and 

glycerol) can have a plasticizing effect, are potentially mobile

and extractable, and can undergo further reactions (such as the 

complexation of free fatty acids with metal ions to create metal 

soaps). The production of LMW species, their further mobility (and potential loss), and specific reactions within the paint 

and ground layers will depend on both internal factors (e.g., the 

nature of the pigments, the binder, their relative concentration, 

manufacturing methods) and external factors (e.g., treatments 

and environmental effects; Van den Berg, 2002; Keune and 

Boon, 2007; Van Loon, 2008).

It is proposed that the stiffness gradient in The Dance is 

consistent with a natural aging process with greater retention 

of plasticizing LMW components within the body of the paint 

and ground and their gradually increasing loss toward the paint 

surface. The constant T2

 value throughout the paint and ground 

layers of The Dinner painting may rather indicate less of these 

components within the deeper paint and ground layers. Since 

the pigments, binder, and layer buildup were identical within the 

paint and ground layers between the two paintings, differences 

can only be reasonably accounted for by external factors. The 

effect of the previous surface treatments cannot be quantified 

since specific environmental factors for each painting remain unknown. However, it is hypothesized that the mobility (and or 

subsequent reaction or loss) of LMW components in the paint 

and ground layers of The Dinner was likely enhanced by solvent 

penetration during previous varnish applications and varnish removals, significantly contributing to its current condition.

FIGURE 3. Visible light and scanning electron photographs of comparable samples in cross section from (top) The Dance and (bottom) The Dinner. The red scale bar denotes 50 nm. The similarity 

of materials and techniques employed in both paintings can be observed. In The Dinner layers appear less discrete, and microfissures 

can be observed.

FIGURE 2. Details (ordinary light, before SRAL treatment) of the 

paint surfaces of (top) The Dance and (bottom) The Dinner. There 

was a noticeable lack of cracking on the paint surface of The Dance, 

whereas The Dinner showed typical age cracks in the paint film 

across the surface.
2 0 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

Previous research has demonstrated the influence of the 

resin on the level of LMW component extraction by the solvent 

in which it was applied (Tsang and Erhardt, 1992; Phenix and 

Sutherland, 2001). However, the effects of penetrating resin 

material on the mechanical structure of the painting and, ultimately, the visual appearance of the painting are also shown 

here. Examining specifically the regions of ground and canvas 

in both paintings, in The Dance there was a gradual gradient 

in decreasing stiffness through the ground and to the back of 

the canvas; in The Dinner the steeper gradient in this equivalent 

region indicates some stiffening within the canvas itself that is 

likely due to the natural resin varnish having impregnated the 

canvas fibers. The NMR data from the ground and canvas layers 

(lowest ~400 μm), alongside the visual and technical results, give 

a strong indication of the effect of resin residues on the mechanical differences evident between the two paintings. 

In varnish removal, solvents could serve to increase penetration of resin residues into the paint, ground, and canvas. This potentially presents a cumulative effect not only from the solvents 

but also, and perhaps critically, from the resin residues. 

The case study here suggests the relatively extreme effects 

of resin varnishes and their residues and thereby inspires further 

questions, including whether the resin effects can be halted or 

even reversed and if different treatment approaches to remove 

the resin more effectively from the entire structure could be beneficial. Whether this should be a weightier consideration in our 

varnish removal treatments depends on the acceptable risk from 

solvent exposure.

RESULTS AND DISCUSSION: SET 2

Whether this risk from the accumulative effects of solvents 

in paint films can be reduced by relatively simple adaptations in 

our varnish removal techniques is a crucial question and is the 

focus of the experiments described below. Small pieces of the red 

oil paint on canvas model (Figure 5) were measured using singlesided NMR (Fife, 2015). Figure 6 shows profiles for both freeand thickened-solvent–treated model samples that experienced 

similar mass gains (5.3% and 5.5%, respectively) immediately 

after treatment. By subtracting the pretreatment fit data from 

the posttreatment data two measurable effects from the treatments can be observed. The T2

 of both treated samples similarly 

increased by approximately one order of magnitude, whereas the 

profile of signal intensity A showed peak widths of ~260 nm for 

FIGURE 5. Detail of model paint film: single red oil paint layer (containing lead white, chalk, and red ochre) on sized linen canvas, naturally aged for around 10 years.

FIGURE 4. Depth profiles of both (top) signal intensity A and (bottom) T2

 for The Dinner and The Dance are shown. The Dance is in 

gray, whereas The Dinner is in orange; the width of the lines indicates the range of the 95% confidence intervals for both parameters. 

The T2

 profile of The Dinner shows a constant T2 value of ~0.10 

ms for the top 600 μm of the painting (0–600 μm on the horizontal 

axis), with an abrupt change in T2

 at a depth of 600 μm. The peak 

in the signal intensity depth profile for The Dinner between 700 and 

1,100 μm is from a piece of tape that was placed on the back of the 

painting prior to measurement to give a location reference. The T2 

profile of The Dance shows a smooth gradient of T2 values throughout the thickness of the painting, ranging from 0.15 ms near the 

surface to ~0.25 ms toward the rear of the paint/ground layer region. 

Distances are accurate to within 100 μm.

0.25

0.50

0.75

1.00

1.25

0

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

1200 600 0

signal intensity [arb] T2 [ms]

depth from painting surface [μm]

1400 1000 800 400 200

The Dinner

The Dance

ca. 300 μm

ca. 250 μm

ca. 150 μm

ground/paint

canvas/ground

canvas
number 5 • 2 1

free solvent and 100 nm for thickened solvent (full width at half 

maximum value).

Other data from similar experiments on the identical sample material with the same experimental conditions and NMR 

parameters also provide insights into the potential effects engendered by these different solvent application methods (Figure 6). 

When two identical samples were both treated with thickened 

solvent (1-methoxy-2-propanol) but with different mass changes 

(i.e., more thickened solvent was applied and retained in one 

of the samples), the T2

 profiles exhibited no differences within 

experimental error. The signal intensity for both samples followed a comparative curve over their depths, with a higher 

profile in the sample with the higher mass gain. In a comparison of similar data from two identical samples treated with free 

solvent (but, again, exhibiting different mass changes of 5.3% 

and 9.6%), the signal intensity for both samples again followed 

comparative curves with an increased profile in the sample with 

greater mass gain. But this time, in the sample where more free 

solvent had been applied and retained, an additional T2

 signal 

was observed (1.2 ± 0.4 and 10 ± 5 ms). 

FIGURE 6. A comparison of the effects on the model paint films from different treatments with free and thickened solvents. Four treatments 

were applied to identical pieces of the model, two thickened-solvent treatments (with a 1.6% and a 5.5% mass gain immediately following 

treatment) and two free-solvent treatments (5.3% and 9.6% mass gain). (top) The thickened-solvent treatments had a narrower range of effect 

(~100 μm, red and yellow) than the free-solvent treatments (~260 μm, green and blue), determined by the full width at half maximum value 

and indicated by the horizontal gray bars. In addition, the three treatments with the smallest percentage gain in mass showed only one T2

 value 

following treatment at approximately 1.0 ms. In contrast, the free-solvent treatment with a 9.6% mass gain (blue) resulted in two different T2 

values, one consistent with the other treatments’ values at 1.2 ms and another at 10 ms. This second T2 suggests a different solvent interaction 

in this sample. (bottom) Integrating the effect of the different solvent treatments shows that the mass change percentage is directly related to the 

amount of effect observed. All integrated values are normalized to the thickened-solvent treatment with the 1.6% mass gain.

9.6% mass gain

free solvent

5.3% mass gain

free solvent

5.5% mass gain

thickened solvent

1.6% mass gain

thickened solvent

1.0 1.9 2.6 4.6

depth from paint surface [μm]

Relative integrated

signal intensity

signal intensity

0

canvas paint surface

600 500 400 300 200 100

1.6% mass gain

thickened solvent

T2 = 0.9 ± 0.4 ms

600 500 400 300 200 100 0

5.5% mass gain

thickened solvent

1.0 ± 0.3 ms

5.3% mass gain

free solvent

600 500 400 300 200 100 0

1.3 ± 0.4 ms

9.6% mass gain

free solvent

600 500 400 300 200 100 0

1.2 ± 0.4 ms

10 ± 5 ms

sum of both

T2

 signals

contribution from 1.2 ms T2 component

3.1
2 2 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

In these comparative experiments on model paint films 

using single-sided NMR, relative differences between the application methods could be observed. Although the maximum level 

(i.e., depth) of solvent penetration is found to remain comparable between two different techniques, the quantity of penetration is reduced with the thickened-solvent application. This is 

considered a significant finding for practice since it is the relative 

magnitude of solvent effects we aim to reduce by adapting application methods and techniques. 

Solvent penetration with both techniques may follow a similar physical model of infiltration (by diffusive and capillary penetration; Michalski, 1990), but it appears that in the case of the 

thickened solvent application the amount of penetrating solvent 

is hindered by the gel matrix (in this case, hydroxypropyl cellulose). This correlates with the gravimetric result that indicates a restricted effective evaporation from the gel matrix.10 In practice, it 

is observed that when using free solvent, immediate penetration of 

liquid solvent can occur, resulting in its appearance in wet patches 

on the back of the canvas. Thickened solvent cannot be observed 

in this way and, in combination with the results presented here, 

may indicate that in the deeper region (below 200 nm) the solvent 

is not present in liquid form but as more dispersed particles. This 

difference may result in reduced solvent effects caused by transport processes, but since the samples immediately after both application methods nonetheless show similar T2

 profiles, the ultimate 

effect of the different application methods on the painting model 

samples must be compared in further experiments.

A further interesting result is the additional signal observed 

when the free solvent is applied with a swab technique as opposed to the thickened solvent in tissue composite method. The 

nature of this secondary type of signal cannot be unambiguously described with these experiments. It did not occur with the 

thickened solvent (even when in relative excess), and it is plausible that a specific swelling mechanism (such as solvent clusters forming in the medium or around particles, etc.) results in 

the ground matrix when excess “free” solvent has been applied. 

What is unambiguous is that the observed signals are not free 

solvent in a bulk state as this solvent has a T2

 in bulk solution 

of 22.65 ms—much larger than any signal observed with either 

treatment method. 

It must be iterated that the region of highest signal intensities (peaks) for both techniques should, in practice, not be in 

the painting layers (as in the unvarnished model) but in the 

varnish being removed. These findings indicate that accurate 

timing of a thickened solvent’s contact with the surface is advised to maximize the benefits of reduced solvent within the 

paintings layers. 

CONCLUSIONS AND FURTHER WORK

The NMR data correlated well with those from the other 

technical and visual examinations and provided greater information on the mechanical properties within the paintings’ layers, 

enabling further interpretations. The combined results supported 

the premise that The Dance could be considered a 400-year-old 

untreated control for The Dinner. Some investigations were 

beyond the scope of this current study, but samples from both 

paintings have been retained for eventual further analyses.

An argument is provided for conservators to carefully consider the mechanical properties of any conservation material 

to be applied to the surface. The case study here indicates that 

treatment-induced changes within the layers of The Dinner plausibly contributed to the development of observable mechanical 

cracks within the paint film. It is hypothesized that the potential 

for natural resins to induce undesirable changes may be more 

significant than is currently considered in much practice not 

only for varnishing but also in varnish removal. The continuing effect of resin remaining within the entire painting structure 

is not necessarily illuminated in cleaning discussions. Perhaps 

considered obvious, it nonetheless deserves explicit discussion 

in research and in practice. Approaches which not only reduce 

solvent penetration, but increase removal of these previously applied materials merit deliberation. 

Utilizing only single-sided NMR, these experiments did not 

aim to provide an in-depth study of solvent effects or to illustrate 

the level of effects that would be seen in practice. However, the 

NMR data can aid in our conceptual modeling of the effects incurred by different application methods. Single-sided NMR has 

proven to be a valuable tool to compare selected varnish removal 

techniques and to better understand changes and the locations of 

those changes within the painting structure.

It is also suggested that other types of conservation treatments that may induce a change (desired or otherwise) in the 

physical properties of the original materials, such as the lining 

or consolidation of paintings, may be more easily examined with 

single-sided NMR. With this analytical technique the penetration of conservation materials might be assessed, and profiles 

might be compared to indicate the efficacy of a particular material and/or treatment approach under consideration.

On the basis of our experimental findings continuing work 

includes comparative measurements after the simulation of multiple cleanings (and full solvent evaporation) to clarify if the different local conditions apparent in the painting model samples 

result in different longer-term (cumulative) effects. Investigating 

the nature of the solvent in a swollen film environment would be 

beneficial, as would comparative studies for the introduction of 

resins. Ultimately, comparative experiments on varnished painting models would be highly informative 

Acknowledgments

The following are gratefully thanked for their contributions: Dr. Paul van Kan for assistance with SEM-EDX analysis 

at SRAL, Marlies Stoter at the Fries Museum for providing information regarding provenance of the paintings, the Alexander 

von Humboldt Foundation for their generous financial support, 

Dr. Erich Uffelman for pXRF analysis, the National Science 

Foundation for a grant funding nondestructive instrumentation 

(NSF MRI 0959625), and the Lenfest Summer Grant program at 
number 5 • 2 3

Washington and Lee University for funding Dr. Uffelman’s travel 

to the Netherlands with the pXRF. 

NOTES

1. Methods and analytical techniques previously used to investigate the effects 

of organic solvents on oil paint films include dimensional changes, gravimetric studies, stress-strain measurements, differential scanning calorimetry, 

thermal mechanical and dielectric measurements, radioisotopic labeling, and 

various and combined chromatographic and spectroscopic methods.

2. Because of the dependence on experimental parameters, A and T2

 values can 

only be related within comparative studies in which the experimental parameters are kept constant. For accuracy in applications within laminar and 

nonhomogeneous systems it may be advisable to correlate depth profiling via 

the examination of layer thicknesses in a removed sample(s). 

3. For NMR experimental details, see G. R. Fife, B. Stabik, A. E. Kelley, J. N. 

King, B. R. Blümich, R. Hoppenbrouwers, and T. Meldrum, “Characterization 

of Aging and Solvent Treatments of Painted Surfaces Using Single-Sided NMR,” 

Magnetic Resonance in Chemistry, 53 (2015): 58–63, doi:10.1002/mrc.4164.

4. For both free and thickened solvents, the sample mass decreased exponentially with solvent evaporation. Half-lives of 72 min for the free solvent and 

116 min for the thickened solvent were determined.

5. Samples were stained with Alexa Fluor (proteins), Rhodamine B (lipids), and 

triphenyltetrazolium chloride (carbohydrates).

6. E. Uffelman (Washington and Lee University) used a Bruker Tracer III-SD, 

Rh anode X-ray tube with with an oval spot size of 4 × 6 mm, and collection 

parameters of 40 kV, 11 μA, and 180s for spectrum accumulation.

7. The total thickness of each painting was measured using calipers of 700 ± 

100 nm. Layer thicknesses were calculated in removed samples (i.e., without 

canvas) using an analytical light microscope. Paint layers were 40 ± 20 nm; 

ground layers were 200 ± 100 nm. With a resolution of 15 nm over a 2.5 × 

2.5 cm area, location can be determined ±100 nm. Although specific layers 

cannot be specified with these certainties, the upper 300 nm can be considered the paint/ground region, with the lower 400 nm being the ground/canvas 

region.

8. The shoulder region in the signal intensity depth profile of The Dance between 650 and 1,100 μm is from the lining canvas adhered to the back of the 

painting during SRAL’s treatment in 2012. A mist lining technique was used 

whereby the original painting is subjected to minimal solvent exposure (from 

reverse), low pressure, and no increased temperature.

9. Increased signal intensity observed throughout the depth of The Dinner may 

indicate resin content.

10. It has been previously shown using radioisotopically labeled solvents (Stulik, 

D., D. Miller, H. Khanjian, N. Khandekar, R. Wolbers, J. Carlson, and W.C. 

Petersen. Solvent Gels for the Cleaning of Works of Art: The Residue Question, ed. V. Dorge [Los Angeles: Getty Conservation Institute, 2004]) that free 

solvent is retained longer in paint films than thickened solvent. The converse 

result shown here is most likely due to the unvarnished nature of the model and 

incomplete clearing procedures employed. These two factors allow for significantly more gel residues remaining on the painting model surface than would 

be anticipated in practice; thus, the previous research findings are not disputed.

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and Applications. Magnetic Resonance Imaging, 16:479–484. http://dx.doi

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Stulik, D., D. Miller, H. Khanjian, N. Khandekar, R. Wolbers, J. Carlson, and W.C. 

Petersen. 2004. Solvent Gels for the Cleaning of Works of Art: The Residue 

Question. ed. V. Dorge. Los Angeles: Getty Conservation Institute.

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qDee6QUc0gg (accessed September 2015).

Fife, G. R., B. Stabik, A. E. Kelley, J. N. King, B. R. Blümich, R. Hoppenbrouwers, 

and T. Meldrum. 2015. Characterization of Aging and Solvent Treatments of 

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the Cleaning of Paintings, ed. Fuster-López. L., A. E. Charola, M. F. Mecklenburg, and M. T. Doménech-Carbó. pp. 85–86. Valencia, Spain: Imprenta 

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with Organic Solvents and Water. Studies in Conservation, 35(suppl. 1):98–

105. http://dx.doi.org/10.1179/sic.1990.35.s1.022.

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Conservation, 10:119–128

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Paintings Affected by Lead Soap Aggregate Formation. Studies in Conservation, 52:161–176. http://dx.doi.org/10.1179/sic.2007.52.3.161.

Maschelein-Kleiner, L., and J. Deneyer. 1981. “Contribution à l’etude des solvants 

utilisés en conservation.” In ICOM-CC 6th Triennial Meeting Preprints, Ottawa, 21st–25th September 1981, ed. D. Grattan, pp. 1–10. Paris: International Council of Museums. 

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Phenix, A. 1998. Solubility Parameters and the Cleaning of Paintings: An Update 

and Review. Zeitschrift für Kunsttechnologie und Konservierung, 12:387–409. 

———. 2002a. Cleaning of Paintings. V&A Conservation Journal Online. Spring, 

Issue 40. http://www.vam.ac.uk/content/journals/conservation-journal/issue

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-paint-and-the-cleaning-of-paintings/ (accessed 8 May 2014). 

———. 2002b. The Swelling of Artists’ Paints in Organic Solvents. Journal of the 

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Solvents on Oil Paint Films. Studies in Conservation, 46:47–60. http://dx.doi

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thesis, University of Amsterdam, Amsterdam. 

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New Insights into the Cleaning of Paintings, ed. Fuster-López. L., A. E. Charola, M .F. Mecklenburg, and M. T. Doménech-Carbó, pp. 43–44. Valencia, 

Spain: Imprenta Llorens.

ABSTRACT. This paper discusses the cross-disciplinary study of a richly illuminated thirteenthcentury manuscript (Fitzwilliam Museum, MS 36-1950), combining codicological, art historical, 

and noninvasive technical analyses. Each of this psalter’s 294 pages is decorated with illuminations 

including 28 full-page miniatures, 10 large historiated initials, 168 small miniatures, and a variety 

of figural and ornamental motifs in the margins. The volume’s extensive and diverse decorative 

program poses challenges to the attribution of its numerous illuminations as well as the amount of 

analytical data needed to help clarify its method of production and to inform its long-term preservation. Needing to prioritize, the first phase of our investigation, whose results are discussed here, 

focused on the full-page miniatures and the historiated initials. The analytical protocol employed a 

cross-disciplinary methodology including paleographical, textual, historical, art historical, and codicological analyses, which were interpreted together with the results of photomicroscopy, infrared 

imaging, visible and near-infrared reflectance spectroscopy, and X-ray fluorescence spectroscopy. Focused on 38 illuminations, this comprehensive investigation produced an extraordinary amount of 

data, which had to be cross-referenced and analyzed in a comparative way. The preliminary results 

of this extensive investigation have so far produced a much clearer picture about the structure and 

authorship of the decoration, and they are presented here as an example of an integrated approach 

to the study of illuminated manuscripts.

INTRODUCTION

Technical analysis of works of art is usually undertaken for two main purposes: 

to establish the histories of production, use, and meaning of objects, including dating, 

localization, ownership, and later modifications, and to understand the material nature 

of objects in view of their preservation. In the case of illuminated manuscripts, for which 

the focus of the technical examination is often the decoration, the main motivation behind scientific analyses is to answer historical and art historical questions. The inherently 

“conservative” approach to manuscripts employed by most conservators today means 

that the exact knowledge of the pigments and painting techniques used in a manuscript 

has limited practical impact on its treatment.1

Knowledge of the painting materials and techniques used in manuscripts can provide a wealth of information on production methods and artists’ skills (and, occasionally, identity), allowing for synchronic and diachronic comparisons of practices both 

within and across artistic media and geographical areas. It can also contribute to broader 

discussions of material culture, art patronage, and the trade of luxury goods. In addition, it can help explain observed degradation phenomena and inform decisions regarding the long-term preservation of manuscripts, if not their interventive conservation. 

Department of Manuscripts and Printed Books, 

The Fitzwilliam Museum, Trumpington Street, 

Cambridge CB2 1RB, UK.

* Correspondence: P. Ricciardi, pr364@cam

.ac.uk

Manuscript received 17 August 2014; accepted 

22 February 2016.

A Holistic, Noninvasive Approach 

to the Technical Study of Manuscripts: 

The Case of the Breslau Psalter

Paola Ricciardi* and Stella Panayotova
2 6 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

Despite major technological developments in recent years that 

allow reliable, noninvasive identification of many artists’ materials (Miliani et al., 2007, 2010; Vagnini et al., 2009; Delaney et 

al., 2010; Rosi et al., 2010; Ricciardi et al., 2012), the scientific 

analysis of works of art on parchment and paper remains an 

underdeveloped field in comparison to the extensive analyses 

carried out on other artifacts, especially easel paintings (Neate 

et al., 2011). One main reason is the widespread conservation 

requirement to employ only noninvasive analytical methods to 

examine manuscripts, avoiding sampling, which is commonly 

practiced on paintings.2

 Even when noninvasive analytical equipment is available, the experimental setup needs to be planned for 

and adapted to individual manuscripts in order to avoid physical 

stress or compromising their integrity.3

This paper discusses the cross-disciplinary investigation of 

a richly illuminated thirteenth-century manuscript, the Breslau 

Psalter (Fitzwilliam Museum, MS 36-1950).4

 It offers an example of an integrated approach to manuscript studies, combining methods from a range of well-established disciplines, such 

as codicology, paleography, history, and art history, with noninvasive technical analyses. The goal is to explore the production 

methods of this complex manuscript and clarify the nature of 

collaboration between the large number of artists entrusted with 

its ambitious illustrative program. 

THE BRESLAU PSALTER

The Old Testament book of 150 Psalms was a central liturgical and devotional text throughout the medieval period. This manuscript, made in thirteenth-century Breslau in Silesia (Wrocław in 

modern-day Poland), is one of the most richly illuminated extant 

psalters (Morgan and Panayotova, 2009: vol. 1, cat. no. 75; Morgan et al., 2011: vol. 1, cat. no. 44). Each of its 294 pages (147 

folios) boasts figural representations and lavish ornamentation. 

Twenty-eight full-page framed miniatures, most facing one another in pairs, are grouped in 10 sections, each introducing one 

of the standard text divisions beginning with Psalms 1, 26, 38, 

51, 52, 68, 80, 97, 101, and 109. These psalms also received 10 

large historiated initials—scenes depicted within the first letter of 

the psalm’s opening word. One hundred sixty-eight small framed 

miniatures adorn the margins of all remaining psalms and the 

canticles (songs from the Old and New Testaments). The calendar 

and litany of saints and the borders throughout the volume are 

populated with hundreds of small scenes and marginal figures. 

This extraordinary repertoire presents serious challenges to—and 

exciting opportunities for—in-depth analyses of artistic collaboration and manuscript production.

Trying to identify all artists’ materials and painting techniques in this manuscript would equal the task of characterizing 

the production of a large painting workshop. Faced with a staggering amount of analytical data, we decided to prioritize the 28 

full-page miniatures and the 10 historiated initials for the first 

phase of our investigation. Only the results obtained on these 

elements of the decoration are discussed here. 

ANALYTICAL PROTOCOL

The variety of painting materials—natural and synthetic, organic and inorganic—employed by illuminators requires the use 

of multiple, complementary analytical methods in order to clarify 

their identity. The wish to characterize artists’ painting techniques 

calls for an even larger set of analytical tools. For a comprehensive interpretation of the manuscript’s methods of production, the 

technical data need to be considered alongside codicological, textual, art historical, and broader historical analyses. 

The investigation of the Breslau Psalter employed the following cross-disciplinary methodology: 

• paleographical analysis of the script for features suggestive of a place and date of origin 

• textual analysis of the contents for evidence of liturgical 

use, patronage, and intended ownership 

• historical analysis of the patronage to clarify the dynastic, aristocratic, and ecclesiastical context of production

• art historical analysis of stylistic, compositional, and 

iconographic features to formulate questions for the 

technical analyses 

• codicological analysis of the manuscript’s structure to 

help clarify artistic collaboration 

• photomicroscopy, focusing on the buildup of flesh tones 

and on the presence of mixtures

• infrared imaging, to investigate the presence and appearance of underdrawing and pentimenti

• spectroscopic analysis by fiber-optic reflectance spectroscopy (FORS) in the ultraviolet–visible–near-infrared 

range (UV-vis-NIR: 350–2,500 nm)

• X-ray fluorescence (XRF), X-ray diffraction (XRD), and 

Raman spectroscopy analysis on selected sites.5

Although still ongoing, these analyses have already produced a clearer picture about the decoration’s authorship, which 

is presented below.

Summary of Paleographical, Textual, 

and Historical Analyses

The dating and localization of the manuscript was determined by combined paleographical, textual, and historical 

analyses. The script, a compressed version of Gothic book hand 

(textualis), and specific letter forms point to thirteenth-century 

central Europe. The liturgical texts establish that the psalter was 

made between 1255 and 1267 in Breslau, Silesia (Morgan and 

Panayotova, 2009: vol. 1, cat. no. 75). A prayer composed for a 

woman and mentioning “God’s servant Henry” (fol. 146r) has 

been linked to the daughter of Duke Albert of Saxony, Helen, 

who married Henry III, Duke of Breslau, around 1257. Although 

relatively few saints specific to Saxony feature in the calendar, 

several saints associated with Prague grace the litany, pointing to 

Helen’s mother-in-law, Anna Přemyslid, who died in 1265. Sister 

of Wenceslas I of Bohemia, Anna was the duchess of Henry II of 

Breslau and mother of Henry III and Vladislav, archbishop of 
number 5 • 2 7

Salzburg. Helen’s marriage and Anna’s death may narrow the 

date range to 1257–1265 if the manuscript was intended for the 

young bride and commissioned by her mother-in-law.

Art Historical Analysis

The Breslau Psalter is the most richly illuminated in a group 

of manuscripts made north of the Alps but containing the work 

of an artist who illuminated an epistolary copied in 1259 for 

Padua Cathedral by the scribe Giovanni da Gaibana.6

 The northern migration of the Paduan style has been associated with Anna 

Přemyslid’s younger son, Vladislav, who studied in Padua before becoming archbishop of Salzburg in 1265 and presumably 

brought the Gaibana Master with him. If the psalter was begun 

by 1265, the year Anna Přemyslid died and Vladislav arrived in 

Salzburg, it would be the earliest of the deluxe Gaibana-style 

manuscripts illuminated north of the Alps. Given its extensive 

pictorial program, work may have continued for several years, 

perhaps under the auspices of Vladislav (Bossetto, 2010; 2015). 

The full-page B(eatus) initial for Psalm 1 (fol. 23v, Figure 1), the 

most accomplished illumination in terms of style, painting technique, composition, and iconography, is unanimously attributed 

FIGURE 1. The Beatus initial on fol. 23v, painted by the Gaibana Master. Fitzwilliam Museum, MS 36-1950. Silesia, Breslau, ca. 1255–1267 © The Fitzwilliam Museum, Cambridge.
2 8 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

to the Gaibana Master. His work is characterized by dignified 

figures with icon-like expressions; elegant drapery with hems defined by crisp white lines and folds forming rhythmical or nestled 

patterns, often accentuated by thick impasto, creating a relief 

effect; juxtapositions of luminous colors in fabrics, highlighted 

in white, geometrically shaped areas and shaded in darker, transparent glazes; soft modeling of faces, with layers built in gradation from a dark gray undertone through carefully blended 

flesh color to red shading and white highlights; flesh and facial 

features outlined in red; and the flowering, broccoli-like trees 

considered to be the artist’s signature feature. 

Ten other images are often attributed to the Gaibana Master 

(denoted GM in the figures and tables): the full-page miniature 

of Christ and the Apostles and the historiated initial for Psalm 

38 (fols. 49v and 51r, Figure 2), as well as eight small miniatures. 

Although their style is closely related to that of the Gaibana Master, they display differences in the modeling of faces and drapery, 

and their execution falls short of the refinement seen on fol. 23v, 

suggesting the involvement of an associate. Analysis of the materials and techniques in these images could clarify the stylistic 

observations and inform broader enquiries: Was the associate a 

disciple trained in the Gaibana Master’s painting techniques or a 

local artist absorbing the Paduan style? Did they collaborate on 

the psalter, sharing materials and perhaps premises, or did they 

work independently? 

Until now, scholarship has focused exclusively on the images attributed to the Gaibana Master and their importance in 

transmitting a new wave of Byzantinizing style and iconography 

from the Veneto to regions north of the Alps (Bossetto, 2010; 

2015; Mariani Canova et al., 2014: no. 12). All remaining figural scenes—well over 200 images—have been ascribed to local 

Breslau-based artists without discussing the nature of their work 

or their relationship to the Gaibana Master (Wormald and Giles, 

1982: 416; Morgan and Panayotova, 2009: vol. 1, cat. no. 75). 

FIGURE 2. The full-page illumination on fol. 49v and the historiated initial on fol. 51r, both traditionally attributed to the Gaibana Master but 

most likely painted by one of his associates. Fitzwilliam Museum, MS 36-1950. Silesia, Breslau, ca. 1255–1267 © The Fitzwilliam Museum, 

Cambridge.
number 5 • 2 9

The present study is the first attempt to examine closely all 38 

major illuminations. Apart from the three usually attributed to 

the Gaibana Master, the remaining 35 seem to have been painted 

by seven main artists and three assistants (fols. 40r, 64r, 104r) 

working in a homogeneous style. Their figure style, facial types, 

modeling of fabrics, and compositional organization of the pictorial space are consistent with contemporary Silesian illumination. Lest we create new “masters of” at this preliminary stage of 

research, we shall assign letters to these hands, listed here with 

the illuminations attributed to them:

A: fols. 18r (Figure 3), 19v, 50r, 73r, 74v, 86r, 87v, 99r, 100v

B: fols. 15v, 16r (Figure 3), 21v, 22r 

C: fols. 17v, 20r, 62r

D: fols. 59v (Figure 3), 60r, 61v, 63v

E: fols. 39v, 103v

F: fols. 72v, 75r (Figure 3), 85v, 88r, 98v, 101r, 113v, 116r 

G: fols. 114r, 115v

The work of these artists will be discussed below, bringing 

the technical analyses to bear on the art historical observations. 

We shall attempt to characterize their palettes, techniques, and 

professional relationships while addressing a number of questions. Was the manuscript a workshop product, undertaken by 

a master with his assistants or a collaborative project between 

independent artists? Did the Gaibana Master make a guest appearance, or was he an integral member of the team? What was 

the extent of interaction between the Breslau artists and the 

illuminators working in the Italian style? Was there a two-way 

exchange of ideas and technical expertise or simply a Paduan 

influence on the Breslau artists? Was any influence or exchange 

limited to stylistic borrowing, or did it run deeper—into the 

choice of specific materials and the adoption of painting techniques? Did the illuminators work side by side, dipping their 

brushes into the same paints? Or were separate leaves dispatched to individual artists, presumably working at different 

premises? The codicological study of the volume may help answer this last question and inform the subsequent discussion, 

which will integrate the technical analyses with the remaining 

investigation.

Codicological Analysis

The manuscript consists of 21 quires—gatherings of parchment sheets folded in half, stacked inside one another, and accommodating distinct sections of text and images. Quires 3–19 

contain the psalms and all major illuminations discussed here.7

Ten of these quires are regular quaternions, composed of four 

folded sheets (bifolios), making eight leaves (folios), or 16 

pages. Quires 7 and 15 are also quaternions, but an additional 

leaf (singleton) with a full-page miniature has been tucked inside each of them (fols. 50, 103). Quires 8, 9, 10, 12, and 14 

vary in composition, from two to five folded sheets (4 to 10 

folios); each was designed in view of accommodating full-page 

miniatures before main division psalms with historiated initials. 

The manuscript’s structure was determined by the desire for lavish illumination. The full-page miniatures are painted on only 

one side of the leaves, a feature reserved for deluxe manuscripts 

and intended to avoid an image on one side of the leaf bleeding 

through. Although the thick parchment of the Breslau Psalter 

could have supported images on both sides of a leaf without 

visual interference, the decision to employ this layout demonstrates that no expense was spared in the manuscript’s design 

and execution. 

Another codicological feature reveals different—and 

evolving—methods of work adopted by individual artists. In the 

earlier part of the volume, red or black frames on the reverse 

of miniatures delineate the painted space, a practice common to 

earlier and contemporary German manuscripts. The frames accompany miniatures by Breslau illuminators but not those by the 

Gaibana Master and his associate. In the later part of the manuscript, the Breslau illuminators abandoned the traditional frames, 

perhaps an aesthetic decision made under Paduan influence. 

The division of labor among the artists confirms that the 

quires were the volume’s main building blocks in terms of pictorial design as well as textual content. Although two or more 

artists collaborated within many quires, miniatures on pages belonging to the same double sheet were painted by a single artist, 

as illustrated in Table 1. Hand A illuminated the central double 

sheets in four quires, whose other miniatures were supplied by 

three distinct illuminators: hands B and C in quire 3 and hand 

F in quires 10, 12, and 14. Hand A also provided a miniature 

on a singleton added to quire 7 between images by the Gaibana 

Master’s associate. 

The division of labor is more complex in the case of double 

sheets containing a miniature and a historiated initial. Usually, 

both were painted by the same illuminator, hand F. In one instance, however (fols. 59v and 62r in quire 8), the miniature and 

the historiated initial were painted by hands D and C, respectively. All other historiated initials lack major illumination on 

the conjoint leaf. 

Technical Investigation

The 38 miniatures and initials selected as the focus of our 

investigation were analyzed with a range of imaging and spectroscopic methods, some in more detail than others. Because 

of the quantity of information needed, we privileged the use of 

FORS in the UV-vis-NIR range to carry out an extensive survey 

of painted areas on these illuminations.8

 Reflectance spectroscopy has been successfully used in recent years to identify a large 

number of pigments, inks, and paint binders on easel paintings 

as well as on works of art on parchment and paper (Strlič et al., 

2010; Ricciardi et al., 2012, 2013a, 2013b; Aceto et al., 2014; 

Delaney et al., 2014; Vetter and Schreiner, 2014). Each spectrum 

can be collected within a matter of seconds, and often, the identification of the main components of the paint layer is immediate, 

making FORS an ideal tool for preliminary technical analysis of 

manuscripts (Aceto et al., 2012, 2014).
3 0 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

FIGURE 3. The full-page illuminations on fols. 18r, 16r, and 59v and the historiated initial on fol. 75r, here 

attributed to four different artists. Fitzwilliam Museum, MS 36-1950. Silesia, Breslau, ca. 1255–1267 © The 

Fitzwilliam Museum, Cambridge.
number 5 • 3 1

Reflectance Spectroscopy: Results on the Breslau Psalter

Reflectance spectroscopy allowed the identification of a 

number of pigments used in the majority of the 38 illuminations analyzed, as exemplified by the sample spectra from fol. 

49v (Figure 4): ultramarine (spectrum A) can be recognized in 

most blue areas by its characteristic absorption centered at 600 

nm, followed by a rise in reflectance with the transition edge 

between about 700 and 720 nm. In a small number of dark/

dull blue areas, ultramarine appears to have been mixed with 

(or possibly layered over) azurite (spectrum B), whose presence 

is clearly revealed by absorption bands at 1,493, 2,285, and 

2,353 nm. A mixture of azurite with a yellow pigment (as yet 

unidentified) was also used in a few green areas (spectrum C), 

although the green pigment of choice was verdigris (spectrum 

D), characterized by a broad absorption centered at 700 nm followed by a slow rise in reflectance, peaking at about 1,320 nm. 

All red areas were painted using vermillion (spectrum E), identified by its sharp transition edge at 595–600 nm. A greater variety 

of pigments was used to paint yellow areas, which are, however, 

relatively scarce throughout the manuscript. The combined use 

of FORS, XRF, and Raman spectroscopy reveals the presence of 

orpiment on four folios in quire 3 and of a yellow earth or ochre 

on four folios in quire 8 and suggests the use of an organic yellow dye on 14 other folios throughout the manuscript. No yellow areas are present on the remaining 16 folios analyzed. 

In addition to the blue, green, and yellow areas, FORS 

analyses also identified pigments and mixtures in the flesh tones 

and white/blue beards of the figures, revealing different patterns 

in the use of materials. Overall, the technical analyses suggest 

the presence of six distinct “palettes,” allowing a preliminary 

division of the miniatures into groups as summarized in Table 

2.9

 For example, Figure 5 shows a selection of FORS spectra of 

flesh tones relative to six different folios, and Figure 6 shows the 

corresponding photomicrographs. The FORS analysis alone cannot identify all the components of these complex mixtures, but 

it helps separate the flesh-tone spectra into groups and identify 

at least some of the individual pigments that characterize each 

group. Flesh tones on folios 16r and 18r are characterized by the 

presence of large amounts of woad,10 as indicated by the strong 

absorption maximum around 660 nm followed by a sharp rise 

in reflectance. Smaller amounts of woad can be identified also 

on fol. 59v. Flesh tones on fol. 49v instead contain azurite, as 

indicated by the presence of absorption bands at about 2,285 

and 2,353 nm, along with a less noticeable band at 1,492 nm. 

Finally, flesh tones on fols. 23v and 75r do not seem to contain 

any blue pigments, but rather are characterized by the presence 

of iron oxide–containing pigments (earths or possibly ochres). 

The spectra from fols. 18r, 23v, and 49v also show an additional 

absorption band at about 2,305 nm, probably related to the 

presence of a lipid-containing paint binder, most likely egg yolk 

(Ricciardi et al., 2012).11 

TABLE 1. Relationship between the quire structure and the position and attribution of the 28 full-page illuminations (FP) and 10 historiated initials (HI) in the Breslau Psalter. S indicates an inserted singleton.

Q3

15v FP B

Q10

72v FP F

16r FP B 73r FP A

17v FP C 74v FP A

18r FP A 75r HI F

19v FP A

Q12

85v FP F

20r FP C 86v FP A

21v FP B 87v FP A

22r FP B 88r HI F

Q4 23v HI GM

Q14

98v FP F

Q6

39v FP E 99r FP A

40r HI assistant 100v FP A

Q7

49v FP GM’s associate 101r HI F

S 50r FP A

Q15

S 103v FP E

51r HI GM’s associate 104r HI assistant

Q8

59v FP D

Q16

113v FP F

60r FP D 114r FP G

61v FP D 115v FP G

62r HI C 116r HI F

63v FP D

64r HI assistant
3 2 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

TABLE 2. Grouping of the major illuminations in the Breslau Psalter based on the results of technical analyses, a list of the signature

pigments and mixtures for each group, and attribution to individual artists. A dash (—) indicates the absence of a specific color or feature in the folio(s).

Category Foliosa Artists Blue Green Yellow Flesh tones Beards

1 23v GM ultramarine verdigris — earths —

2 49v, 51r GM’s associate ultramarine, azurite verdigris, azurite 

mixture — azurite azurite

3 18r, 19v, 50r, 73r, 74v, 

86r, 87v*, 99r, 100v*

A ultramarine verdigris organic/— woad ultramarine

4 15v, 16r*, 17v, 20r, 21v*, 

22r, 62r*, 64r B, C ultramarine verdigris orpiment/— woad woad

5 59v, 60r, 61v, 63v D ultramarine verdigris earth/ochre woad ultramarine

6

39v, 40r, 72v, 75r, 85v, 

88r, 98v, 101r, 103v, 104r, 

113v, 114r, 115v, 116r

E, F, G ultramarine verdigris, azurite 

mixture organic/— earths ultramarine

a

No blue beards or yellow areas are present in the folios marked by an asterisk (*), meaning that they could match both categories 3 and 4. Their assignment here is based 

on the presence of bright pink (present on all other folios in category 3) versus a muted tan color (typical of folios in category 4) in the fabrics.

FIGURE 4. Sample FORS spectra from blue, green, and red areas on fol. 49v. See text for an interpretation of each spectrum. Fitzwilliam Museum, MS 36-1950. Silesia, Breslau, ca. 1255–1267 © The Fitzwilliam Museum, Cambridge.
number 5 • 3 3

DISCUSSION

A systematic comparison of the information obtained by the 

different methods employed for this cross-disciplinary study reveals considerable agreement between the art historical, codicological, and technical analyses for the majority of illuminations 

examined. Tables 1 and 2 summarize the overall results.

The results of the technical analyses support the art historical differentiation between the Gaibana Master, responsible for 

fol. 23v, and the associate who illuminated fols. 49v and 51r. The 

Gaibana Master’s use of a delicate violet color, obtained with 

a mixture of vermillion and ultramarine blue, is unique in the 

manuscript. Another major difference is the painting of flesh: unlike the Gaibana Master, who chose earth pigments, his associate 

made prolific use of azurite in flesh tones and beards, as well as 

in blue areas and green mixtures. None of the Breslau artists 

favored azurite, despite—or perhaps because of—its wide availability in central Europe. The varying choices of blue pigments 

suggest that the Gaibana Master, his associate, and the Breslau 

artists worked independently; they were neither supplied with 

nor expected to share the same materials.

Although the associate emulated the Gaibana Master’s style 

successfully, his choice of materials, especially for the flesh and 

beards, is markedly different. This difference suggests that he 

was neither a disciple trained by the Gaibana Master nor a close 

collaborator on the Breslau Psalter, sharing pigments and presumably premises. Nevertheless, the close and confident adherence to the Paduan style implies ready access to the Gaibana 

Master’s work. If the associate did not come with the Gaibana 

Master from Padua, he may have encountered him upon his arrival in Salzburg. Although the Gaibana Master contributed a 

single image in quire 4, the associate painted 10, including small 

miniatures in quires 6 and 7.12 These quires may have been sent 

to Salzburg, or both artists may have visited Breslau, with the associate perhaps staying on and transmitting his knowledge of the 

Gaibana Master’s style and iconography to the Breslau artists. 

Among the seven local artists, two stand out as the most 

accomplished: hands A and B. They share certain features with 

the Gaibana Master and his associate: the nestled folds, impasto 

outlines and shading glazes on fabrics, and the red outlines of 

flesh and facial features. However, their faces lack delicacy. 

Without careful blending, the modeling of flesh reveals the layers, shading, and highlights. Hand A introduces monumental 

figures, gold-tooled and painted halos, and liquid gold over details first colored in green, all implying that he might have been 

trained as a panel painter rather than an illuminator.13 He favors 

trichromatic highlights on green drapery, white scumble on blue 

fabrics, bright pink robes, and light yellow areas painted with an 

organic dye. His pink flesh tones have blue undertones obtained 

with woad, whereas the blue/gray beards of his older characters 

contain ultramarine blue. The use of large amounts of woad in 

flesh tones is shared by hand B, who, unlike hand A, uses the 

same pigments for beards and prefers soft tan as a surface hue 

for faces. His figures are elegant but less imposing in proportion 

to the overall pictorial space. His range of greens is more limited 

and of inferior technical execution, with large areas of flaking 

pigment revealing the underdrawing. His pink fabrics are transparent and muted in hue. Hand C follows the first two artists 

closely, but his style is dry and linear, his crowded compositions 

lead to oversights (the domes on fol. 17v are suspended in thin 

air), and his dwarflike figures are devoid of elegance, their exaggerated facial features bordering on the grotesque. His palette is 

the same as the one employed by hand B. 

Hand D, who was responsible for a cluster of four miniatures, emulated the delicate facial expressions and broccoli-like 

trees of the Gaibana Master, but his drapery folds are as schematic and his compositions as crowded as those of hand C. He 

also mixed woad in his flesh tones, but his palette is strongly 

characterized by the use of an ochre pigment in yellow areas.

The remaining three artists all employed the same palette, 

characterized by the lack of blue pigments in their flesh tones. 

Hand F painted eight large images in four clusters, collaborating with hand A in three of them (quires 10, 12, 14). His salient 

features include gold-tooled frames, elongated figures with small 

heads, elaborately knotted belts and “ankle warmers,” and gray 

outlines of limbs; the few exceptions to the latter include the 

miniature on fol. 72v, where the artist adhered to the red outlines 

employed by all other artists and painted a hem in liquid gold, 

perhaps to mirror those by hand A on the facing page. 

FIGURE 5. Sample FORS spectra of flesh tones on six different folios, each by a different artist and corresponding to one of the groups 

listed in Table 2.
3 4 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

Hands E and G painted two miniatures each. Hand E is identified as the only artist in the manuscript to outline red drapery 

folds in black. Hand G emulated hand A’s stylistic features14 but 

appears to display a strong interest in the Gaibana Master’s iconography,15 whereas the remaining local artists seem less inclined 

to borrow directly from the Gaibana Master or his associate. 

The authorship of the three historiated initials on fols. 40r, 

64r, and 104r remains problematic. It is possible that they were 

painted by three different artists who may have been among the 

illuminators responsible for the minor decoration throughout 

the volume.16 Although the production of this deluxe manuscript 

was carefully planned and managed, the completion of such an 

ambitious decorative program required the involvement of numerous artists, resulting in individual idiosyncrasies within the 

overall design.17

Furthermore, as in the case of the Gaibana Master and his 

associate, stylistic similarities between the Breslau artists do not 

always correspond to shared materials and techniques. Hand A’s 

accomplished work, prominent role throughout the volume, and 

stylistic influence on his collaborators suggest that he was an established artist, probably entrusted with managing the provision 

of the major illuminations. His choice of materials, however, was 

not followed by hands B and C, who adhered to his style, or by 

hand F, who collaborated with him in three quires. Likewise, 

hand D stands in isolation from other artists in his pigment preferences. Conversely, the use of a common palette did not always 

result in an artistic homogeneity: hands E, F, and G employed the 

same pigments but retained their individual stylistic peculiarities. 

By contrast, hands B and C shared not only stylistic features but 

also specific painting materials and techniques. 

FIGURE 6. Micrographs (originally taken at ×7.5 magnification) of the flesh tone areas whose FORS spectra are shown in Figure 5.
number 5 • 3 5

CONCLUSIONS

The combined codicological, art historical, and technical 

analyses of the 38 major illuminations in the Breslau Psalter demonstrate the benefits of an integrated, cross-disciplinary approach. 

The benefits are particularly clear in the case of this exceptionally 

complex manuscript involving numerous illuminators and combining stylistically and geographically distinct artistic traditions.18

The integrated approach answered many of the questions about 

production methods and artistic collaboration. 

The illuminators of the major images do not seem to have 

belonged to a single workshop. Some of them were independent 

artists (hand D), others may have been regular collaborators 

(hands B and C), and yet others seem to have come together for 

this project (hands E, F, and G). All of them were most likely 

gathered to ensure the timely completion of the ambitious decorative program. The brief, but brilliant, guest appearances of 

the Gaibana Master and his associate were probably intended to 

speed up the process and enhance the quality of the final product. Rather than a two-way exchange of ideas and technical 

skills, their interaction with the German artists resulted in borrowing of isolated stylistic and iconographic features by some, 

but not all, of the local illuminators. Hand A, probably a painter 

at the ducal court, may have overseen the project, but without 

imposing a uniformity of style, materials, or techniques. Some of 

the illuminators (hands E, F, and G) may have worked side by 

side, sharing pigments, but others probably received individual 

bifolios dispatched to their own premises. 

These preliminary suggestions, based on the partial analyses 

of 38 images, may be modified by cross-disciplinary analyses of 

the small miniatures and marginalia at the next stage of research. 

This next step may establish the degree of interaction between 

the main artists discussed above and the lesser hands responsible for the minor decoration. Future work will also focus on 

the identification of brown and pink/tan pigments, as well as 

paint binders. An enriched and refined characterization of painting materials and techniques in both the major and minor decoration would offer a truly comprehensive understanding of this 

complex volume and provide a sound foundation for the analyses of contemporary manuscripts. 

NOTES

1. The exact knowledge of paint binders, however, may have a stronger impact 

on conservation treatments, which is just one of the reasons why the noninvasive identification of paint binders on manuscripts is one of the most pressing 

challenges faced by conservation science at present.

2. The fragility and light sensitivity of the paint layers, as well as the physical 

shape and dimensions of the manuscripts, greatly reduce the number of analytical methods that can be used on bound volumes. The technical analysis 

of manuscript cuttings and individual leaves that were cut out of their parent 

manuscript at some point in the past is easier from the practical point of 

view and more similar to the analysis of small panel paintings. The issues of 

fragility and light sensitivity, however, are still present, as are the additional 

complications in the interpretation of spectroscopic data discussed further on 

in this paper in the section on reflectance spectroscopy.

3. For a discussion and suggestions for appropriate analytical protocols for the 

analysis of manuscripts, see Maurizio Aceto, Angelo Agostino, Gaia Fenoglio, Monica Gulmini, Valentina Bianco, and Eleonora Pellizzi, Non invasive 

Analysis of Miniature Paintings: Proposal for an Analytical Protocol, Spectrochimica Acta Part A, 91 (2012): 352–359, http://dx.doi.org/10.1016/j.saa

.2012.02.021; Paola Ricciardi and John K. Delaney, Combining Visible and 

Infrared Imaging Spectroscopy with Site-Specific, in-Situ Techniques for Material Identification and Mapping, Revista de História da Arte, Série W, 1 

(2011): 252–261. 

4. The most recent discussions of the manuscript’s illumination and patronage 

are Fabio L. Bossetto, Il Maestro del Gaibana: un miniature del Duecento fra 

Padova, Venezia e l’Europa (Milan: Silvana Editoriale, 2015); Nigel Morgan 

and Stella Panayotova, A Catalogue of Western Book Illumination in the 

Fitzwilliam Museum and the Cambridge Colleges, part 1 (London: Harvey 

Miller, 2009), vol. 1, cat. no. 75; Nigel Morgan, Stella Panayotova, and Suzanne Reynolds, A Catalogue of Western Book Illumination in the Fitzwilliam Museum and the Cambridge Colleges, part 2 (London: Harvey Miller, 

2011), vol. 1, cat. no. 44; Stella Panayotova (ed.), Colour: The Art and Science of Illuminated Manuscripts (London: Harvey Miller, 2016), cat no. 26 

and 119–135. They sum up earlier discussions and list all essential previous 

literature, which is not repeated here for lack of space. The technical analysis 

was carried out within the context of the MINIARE (Manuscript Illumination: Non-Invasive Analysis, Research and Expertise) research project (http://

www.miniare.org).

5. Combined XRF-XRD measurements were carried out by Philippe Walter and 

Hélène Rousselière from the Laboratoire d’Archéologie Moléculaire et Structurale in Paris, within the context of the CHARISMA-MOLAB (Cultural 

Heritage Advanced Research Infrastructures: Synergy for a Multidisciplinary 

Approach to Conservation and Restoration—Mobile Laboratory) project. 

Raman analyses were undertaken by Andrew Beeby and Kate Nicholson 

from Durham University. 

6. Biblioteca Capitolare, MS E 2, Padua, Italy; Giordana Mariani Canova, 

Marta Minazzato, and Federica Toniolo, I Manoscritti Miniati della Biblioteca Capitolare di Padova, vol. 1 (Padua: Istituto per la Storia Ecclesiastica 

Padovana, 2014), no. 12.

7. For an introduction to codicological analysis, see Bernhard Bischoff, Latin 

Palaeography: Antiquity and the Middle Ages (Cambridge: Cambridge University Press, 1990), 5–45, http://dx.doi.org/10.1017/CBO9780511809927.

8. The FORS analysis was carried out using a FieldSpec4 spectroradiometer 

(ASDi/Panalytical) with a bifurcated fiber-optic probe, with the ability to collect reflectance spectra between 350 and 2,500 nm. Each spectrum was the 

average of 64 measurements; over 600 painted areas of about 3 mm in diameter were surveyed by this method. 

9. In the case of flesh tones, in particular, the table lists only the main or most 

characteristic component of each complex mixture.

10. The presence of woad, rather than indigo, can be hypothesized on the basis 

of the geographic origin of this manuscript. However, FORS, like many other 

techniques, cannot distinguish between these two colorants.

11. The spectral evidence suggests the presence of a paint binder different from 

the one (or ones) used in other parts of the decoration. Such evidence is most 

clear in areas of flesh on several folios (e.g., 18r, 23v, 49v, 73r, 74v, and 100v), 

all of which have been attributed to the Gaibana Master, to his assistant, and 

to hand A, as well as in the beards of figures on fol. 23v. There is certainly 

scope for further investigation; we hope among other things to perform Fourier transform infrared spectroscopy analysis and near-infrared hyperspectral 

imaging on these areas to help clarify the nature of this material and to verify 

the extent of its presence at least across the 38 major illuminations. 

12. Technical examination of these small miniatures still has to be undertaken, 

but the art historical analysis strongly suggests that they were painted by the 

Gaibana Master’s associate.

13. Should the substantial presence of an egg yolk binder be confirmed on folios 

painted by hand A, this information would additionally support the suggestion that he may have been trained as a panel painter and as such very familiar with egg tempera as a painting medium. 

14. These include his monumental figures, chromatic juxtapositions, drapery 

folds, and halos.

15. For example, he transferred the Gaibana Master’s Byzantine iconography 

of the Deësis, showing the Virgin and St. John the Baptist interceding with 

Christ for human salvation (fol. 23v), into his own composition (fol. 115v).

16. Their overall palette is most similar to the work of hands B and C (fol. 

64r) and E, F, and G (fols. 40r and 104r), respectively. However, the initial 

on fol. 40r includes a facial type and the sophisticated handling of green 
3 6 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

characteristic of hand A, suggesting that the leading Breslau artist may have 

collaborated with an assistant on this image. The possible collaboration 

of different artists on the same miniature exemplifies the Breslau Psalter’s 

complexity.

17. Among these differences are the absence or presence (in black or red) of 

frames on the versos of full-page miniatures, the insertion of two miniatures 

on singletons (fols. 50r, 103v), the marked increase of whimsical marginalia 

from quire 11 onward, the presence of orange areas painted with red lead 

only on one bifolio (fols. 127–134), and the stylistic change in the small miniatures in quires 17–19. 

18. The initial phase of this work has already highlighted the pressing need for a 

flexible tool allowing for coherent storage, structure, annotation, and visualization of the large amount of text, images, and analytical data in different 

formats generated during the project. An initial step has been taken during 

the “Digital Layers” project, which has resulted in the development of a digital image annotation tool and an online research resource (www.fitzmuseum

.cam.ac.uk/illuminated) which features, among others, the Breslau Psalter. 

The need to better integrate imaging and analytical technologies used by conservators and cultural heritage scientists for the study of works of art was 

also the topic of an experts’ meeting held at the Getty Conservation Institute 

in 2013. One of its most immediate outcomes was a report including a review of case studies and a list of recommendations for future research on this 

topic, posted on the institute’s website (http://www.getty.edu/conservation/

our_projects/integrating_imaging.html, accessed 3 August 2016).

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Bianco, and Eleonora Pellizzi. 2012. Non invasive Analysis of Miniature 

Paintings: Proposal for an Analytical Protocol. Spectrochimica Acta Part A,

91:352–359. http://dx.doi.org/10.1016/j.saa.2012.02.021.

Aceto, Maurizio, Angelo Agostino, Gaia Fenoglio, Ambra Idone, Monica Gulmini, 

Marcello Picollo, Paola Ricciardi, and John K. Delaney. 2014. Characterisation of Colourants on Illuminated Manuscripts by Portable Fibre Optic UVVisible-NIR Reflectance Spectrophotometry. Analytical Methods, 6:1488–

1500. http://dx.doi.org/10.1039/c3ay41904e.

Bossetto, Fabio L. 2010. Splendori a corte: Il Salterio Thompson di Cambridge. 

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Bossetto, Fabio L. 2015. Il Maestro del Gaibana: un miniatore del Duecento fra 

Padova, Venezia e l’Europa. Milan: Silvana Editoriale.

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Thoury, Michael Palmer, and E. René de la Rie. 2014. Use of Imaging 

Spectroscopy, Fiber Optic Reflectance Spectroscopy, and X-ray Fluorescence to Map and Identify Pigments in Illuminated Manuscripts. Studies 

in Conservation, 59(2):91–101. http://dx.doi.org/10.1179/2047058412Y

.0000000078.

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and Infrared Imaging Spectroscopy of Picasso’s Harlequin Musician: Mapping and Identification of Artist Materials in Situ. Applied Spectroscopy,

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Press.
ABSTRACT. This paper presents the results of a technical investigation of two panel paintings 

from the collection of the Suermondt-Ludwig-Museum, Aachen, formerly attributed to a Burgundian workshop and more recently to an unknown Spanish workshop. The study applied methods 

of noninvasive analysis that aimed to understand the painting process and the conservation history 

and to reevaluate the attribution of the panels. Noninvasive analysis was carried out using stereomicroscopy, ultraviolet fluorescence, raking light topographical studies, X-radiography, infrared reflectography, and portable X-ray fluorescence. Microsamples were taken for examination of layers 

and material analysis using scanning electron microscopy–energy dispersive X-ray spectroscopy and 

Fourier transform infrared spectroscopy. The results of the technical study informed both the attribution of the works to the Kingdom of Aragon, Catalonia, or the Province of Valencia and decisions 

for the conservation treatment of the panels. The study also corroborated that the paintings are 

remnants of a much larger unknown altarpiece. At present, no workshop attribution can be established, but it is clear that the paintings are characteristic of a small group of master artists-craftsmen 

practicing at the end of the fifteenth century.

INTRODUCTION

This paper presents the results of a technical examination of two panel paintings 

depicting biblical scenes from the lives of St. John the Evangelist and St. John the Baptist: 

St. John the Evangelist Drinking from a Poisoned Chalice and The Beheading of St. John 

the Baptist.

1

 The panels belong to the collection of the Suermondt-Ludwig-Museum in 

Aachen, Germany (Figure 1).2

 The panels came to the conservation studios of the Stichting Restauratie Atelier Limburg (SRAL) in Maastricht, the Netherlands, for research and 

treatment in 2012. 

The panels were donated to the museum in 1914 by Louis (Ludwig) Beissel (1842–

1914), an entrepreneur and friend of Robert Frederick Suermondt (1844–1919), son 

of the founder of the museum.3 The panels are unattributed, and few pertinent archival 

documents exist, certainly none preceding accession. Except for the material evidence on 

the panels themselves, only two brief records dating to the latter part of the twentieth 

century provide any information on prior conservation treatments.4

The panels were attributed on accession to a medieval Burgundian workshop.5

 However, in the catalog to the 2006 exhibition El Greco, Velázquez, Goya: Five Centuries of 

Spanish Masterpieces at the Szépművészeti Múzeum (Museum of Fine Arts), Budapest, 

attribution of St. John the Evangelist to a Burgundian master practicing in France or the 

1

 Mauritshuis/Atelier Albrecht, Henry Hagalaan 

22, 2273 DT Voorburg, The Netherlands.

2

 Restauratie Atelier Daugherty, Paramaribostraat 

61, 1058 VH Amsterdam, The Netherlands.

3

 Cultural Heritage Agency of the Netherlands/

Saskia van Oudheusden Schilderijenrestauratie, 

Sint Jorisstraat 10, 5211 HB ‘s-Hertogenbosch, 

The Netherlands.

4

 Hamilton Kerr Institute Cambridge, Hoge Zand 

12 2512 EM, The Hague, The Netherlands.

5

 Stichting Restauratie Atelier Limburg, Avenue Ceramique 224, 6221 KX Maastricht, 

The Netherlands.

6

 Suermondt-Ludwig-Museum, Wilhelmstraße 

18, D-52070 Aachen, Germany.

7

 London Studio, The Hamilton Kerr Institute/

Simon Bobak Conservation, 153A Ebury St., 

London SW1W 9QN, UK.

8

 Department of Chemistry and Biochemistry, 

Washington and Lee University, 204 W Washington St., Lexington, Virginia 24450, USA.

* Correspondence: M. Albrecht, marya.albrecht

@live.nl

Manuscript received 29 October 2015; accepted 22 February 2016.

Unraveling the History of Two 

Fifteenth-Century Spanish Panels

Marya Albrecht,1* Melissa Daugherty,2 Saskia van Oudheusden,3

Lieve d’Hont,4

 Kate Seymour,5 Michael Rief,6 Ray Marchant,7

and Erich Uffelman8
3 8 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

Low Countries was dismissed on the basis of stylistic analysis.6 

Instead, solely on the basis of connoisseurship, Spanish authorship was proposed. 

The present study reexamines the question of the origins of 

the panels, investigating the original materials and techniques 

used to create the works, the condition of the panels, and their 

condition history. A number of methods for technical examination were employed to provide answers to specific questions. Resources were limited in terms of both access to advanced analytical 

equipment and finances. The results of the undertaken technical 

FIGURE 1. Unknown master. (left) St. John the Evangelist Drinking from the Poisoned Chalice (GK84a) and (right) The Beheading of St. John 

the Baptist and the Feast of Herod (GK84b). Circa 1475. Photographs before treatment. Image: SRAL.
number 5 • 3 9

study were contextualized by reviewing the contemporary (Spanish) cultural and historical milieu, as described in original sources 

and through a literature study. Combining the outcomes of both 

investigations permitted a more holistic approach wherein the 

conclusions of each study supported the other. 

ICONOGRAPHY

The panels depict the feast of Herod with the decapitation of 

St. John the Baptist and St. John the Evangelist drinking from a 

chalice containing a poisoned liquid. These two well-established 

events in the lives of these saints are described in the New Testament (Matthew 14:1–127

 and the Acts of John,8 respectively). 

Placing the two Suermondt-Ludwig panels in this narrative provided a starting point for the iconographical investigation. The 

panels show scenes from the end of one saint’s life and the key 

event in the other saint’s life. A photograph from 1914 shows 

both paintings displayed in one frame, which consists of a partitioned rectangular construction with two elaborate, pinnacled 

canopies.9

 However, juxtaposing the panels in this frame is discordant with iconographical convention. In altarpieces dedicated 

to more than one saint, medieval protocol would show a similar 

number of scenes for each saint and odd numbers would prevail. 

Thus, the presence of one image central to the life of one saint 

and a martyrdom image of another saint suggests that scenes 

are missing. Prominent additional scenes from the lives of these 

saints would include, for St. John the Evangelist, his martyrdom 

(immersed in a vat of boiling oil), the raising of Drusiana, and 

the writing of the Book of Revelation on the island of Patmos 

and, for St. John the Baptist, the annunciation to Zacharias, the 

saint living in the wilderness, and the baptism of Christ.10

Therefore, when considered in an iconographical context, 

it is likely that the panels once formed part of a larger altarpiece dedicated to the lives of St. John the Baptist and St. John 

the Evangelist. The panels are thus two surviving fragments of 

a much larger whole. Both Saints John were very popular in 

fifteenth-century Spain, and there are many examples of large 

and small retablos dedicated to them in the region the researchers focused upon: the Kingdom of Aragon, Catalonia, and Valencia.11, 12 One example is the 1432 Vinaixa (Les Garrigues, 

Catalonia) Altarpiece of the Saints John by the Catalan master 

Bernat Martorell (died 1452), in which the lives of both saints 

are depicted in the lateral columns.13 The story of each saint begins in the upper tier and culminates in the lower corners of the 

sotto banco. The moment of St. John the Evangelist’s martyrdom 

as he is boiled in oil is shown on the left, and the decapitation 

of St. John the Baptist is depicted on the right. The imagery depicted in Martorell’s retablo is similar to that in the two existing 

Suermondt-Ludwig panels. 

The Martorell example is typical of late medieval Spanish 

altarpieces. Large pictorial altarpieces (retablos) of this period 

from the northeastern coastal provinces of Spain often consisted 

of several sections in which a narrative is used to educate the illiterate viewer. The section above the altar is called the banco.

14

The slightly wider central portion of the retablo is dedicated to 

the patron saint of the altarpiece, a triumphant Christ, or the 

Virgin Mary and is crowned with an ático depicting the Calvary. 

This section is flanked by vertical columns called calles, which 

contain narrative scenes, separated by gilded carved wooden 

traceries showing moments in the lives of the saints. Threedimensional canopies often top the altarpiece. These are called 

guardapolvo. Larger altarpieces also contained a sotto banco

directly above the altar. This typically shows important acts of 

the saints, such as their martyrdom, flanking a resurrected or 

entombed Christ. The authors presume that the missing sections 

of the Suermondt-Ludwig altarpiece would conform to this template. This context was considered when interpreting the results 

of the technical examination.

STRUCTURAL EXAMINATION OF THE PANEL: 

SUPPORT CONSTRUCTION AND PREPARATION

The starting point for the technical investigation was an assessment of the condition of the panels, including the wooden 

supports, and the materials used for ground and paint layers. 

The original wooden support used for St. John the Evangelist

(see Figure 2) is badly damaged by wood-boring insects and 

past treatments; however, close examination provided information about its original construction. The support of St. John the 

Baptist provided no additional information as it was removed 

entirely when the decorative layers were transferred to a new 

support in the 1970s.15 However, traces of the original construction are still evident in the preparatory and paint layers used for 

both panels. These will be described below in the appropriate 

context.

Panel Construction

The original panel support of St. John the Evangelist now 

consists of two pinewood boards of ~4 cm thick. The boards differ 

in width, measuring 41 and 9 cm, respectively, from left to right 

and are butt joined with one centrally placed wooden dowel.16

The height of the panel is roughly 104 cm (Figure 3). The top 

and bottom edges are not parallel to each other. The decorated 

surface does not extend to any of the edges of the panel, and the 

undecorated wood differs in extent on each side. The two vertical edges of the decorative surface (at the canvas level, see below) 

show signs of being cut with a sharp edge, such as a knife. The 

scene is framed at the top by a typical superimposed carved and 

gilded wooden tracery attached directly to the wooden support. 

The three-dimensional architectural framework that is typically 

situated between the narrative scenes has been removed. There 

are marks, however, along the border of the decorated surface 

that indicate these were present on both vertical edges. The architectural elements were intended to be three-dimensional and 

provide a “space” or “niche” in which the scene is played. The 

tracery spatially links the depicted scene with the architectural 

frame, as shown in the reconstructed frame in the 1914 archival 
4 0 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

photograph and in contemporary exemplars. The reverse of the 

panel is covered with a number of nonoriginal coatings in white 

(earlier) and in red (later), providing evidence of past nonoriginal 

cross-board supporting systems. The bottom edge of the panel is 

beveled at the reverse to a distance of ~10 cm and is badly damaged. There are (three) plugholes inserted into this undecorated 

bottom edge, likely to fix the support into a framing element. 

Saw marks are clearly visible on three edges (top, left, and right) 

of the panel. Dissected insect tunnels are present along the righthand edge.17 The larger board contains the pith of the tree trunk 

and (badly damaged) sapwood on both edges. 

The presence of these typically discarded elements of the 

timber suggests that the carpenter who constructed the large 

retablo used the source material, thick unprocessed pinewood 

boards, economically, as was typical in the construction period 

proposed.18 It would be expected that other selected boards 

would be at least of similar quality and width, and multiples 

would be used to form the section (Figure 3). The support, now 

cut to “frame” the pictorial layers and iconographical image, 

must have been much larger, incorporating perhaps two or three 

additional lateral scenes of similar size. Although the original 

support of the second panel, St. John the Baptist, is no longer in 

existence, the preparatory and decorative layers present damage 

that suggests similar placement of a vertical joint and cross-grain 

battens, making it likely that boards of identical width were also 

used to construct this support. Additionally, the presence of the 

joint in an asymmetrical noncentral position indicates that this 

support also extended to the side.

This evidence points to the placement of both paintings in 

a lateral calle of a larger altarpiece. The central panel, together 

with the ático, was typically constructed independently of the 

calles. Typically the calles consisted of one piece from top to 

bottom or several smaller “tiers,” depending upon the overall 

size of the retablo. The wood grain of the larger individual elements would run either vertically or horizontally, contingent on 

the overall size of the retablo, as the board orientation would be 

efficiently used by the carpenters to achieve the maximum size, 

using the minimum about of timber.19 Here in the SuermondtLudwig panels, the grain direction runs vertically in both supports, which suggests that these panels come from a vertical calle.

The proportions of the images also suggest a vertical orientation and lateral placement of the panels. The image size 

of both panels is consistent, measuring ~92 × 48 cm, giving a 

proportional relationship of almost 2:1. The design of Spanish 

altarpieces was typically based on harmonious proportional 

symmetry. The central section, based on the golden ratio, would 

be twice as wide and as high as the individual elements of the 

calle.

20 However, without more sections of the missing retablo, 

the existing evidence is insufficient to support further conjecture 

or even to speculate on the size of the entire original retablo; 

however, it must have been large, measuring meters in height 

and width. Existing floor-to-ceiling fifteenth-century retablos are 

still in situ in the Cathedral of Barcelona and other churches in 

the region. Dismantled contemporary examples from the entire 

region are on display in the Museum of Fine Arts in Valencia 

and the National Museum of Catalan Art in Barcelona. These 

contemporary examples provide a visual context of how the 

Suermondt-Ludwig panels would have appeared in their original surroundings. An attempt to establish a connection between 

other dispersed panels based on stylistic grounds has recently 

been made.21 Further material-technical study of all proposed 

sections will be necessary to confirm this hypothesis. 

FIGURE 2. Reverse of the original support of St. John the Evangelist. Image: SRAL.
number 5 • 4 1

Assembly Technique

Studying the traces of original construction elements provided further evidence for the geographical origin of the panels. 

Construction and assembly of Spanish retablos were customarily 

done by specialist craftsmen in a workshop separate from where 

the painting and gilding were carried out. Typically, fifteenthcentury Spanish panels were assembled using locally sourced 

wood, most commonly pinewood in Castile and Aragon.22 After 

seasoning of the timber, the supports were constructed by joining several boards together using wooden or metal dowels, or 

pegs, to achieve the correct alignment. Glue was used to adhere 

the boards together. How the joint was constructed is indicative 

of workshop practice. However, in the case of the SuermondtLudwig panel no trace of glue was found in the joint, and only 

one large, round wooden dowel was placed centrally in the joint. 

Although the former can be explained as a regional or workshop 

practice, the latter again points to a resizing of the panel.23

Carpenters working in the northwestern region of medieval 

Spain often used less seasoned wood, combined with cross battens, 

dowels, and no adhesive in the joints, to construct panel supports, 

tabernacles, altar fronts, and other large wooden objects. These 

joints are called uniones vivas. Roughly hewn, wide, and thick 

boards of considerable length were used to make wooden constructions quickly.24 Boards of these dimensions and thickness 

would have exerted considerable tension as the moisture content 

diminished and would have had a tendency to twist or warp on 

drying. This proclivity to warp would be inhibited by the cross 

battens, but the boards would shrink in a lateral direction, producing gaps between them. If glue were present during this process, 

fractures would ensue in the boards themselves. Therefore, the absence of fractures relating to drying (and thus evidence that glue 

had been used in the joint) and the absence of the remains of any 

glue in the joint suggest a regional construction technique specific 

to contemporary provinces of Aragon, Catalonia, and Valencia. 

Once the retablo support was constructed, it was left in the 

chapel or church to await the next step. The application of decorative layers often occurred in situ because of the large scale of 

these retablos even if the larger altarpieces were constructed in 

sections. This phase in the decoration process could vary from 

months to years and also served to illustrate how the material behaved in situ. The first step in the process of painting and gilding 

FIGURE 3. Diagram showing the possible construction of the panel support. Three or more boards of 

even width are joined together using crossbeams. The panel of St. John the Evangelist has been cut out 

of a section like this and consists of two boards 9 and 41 cm in width.
4 2 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

would have been cleaning the wooden supports and correcting 

imperfections that occurred during the waiting period.25 This 

step involved filling the narrow gaps between the boards that 

appeared as the wood lost moisture content. Gaps were filled 

in a number of ways. Again, the manner in which this occurred 

would likely be indicative of the practice of a particular workshop. Examples have been documented in which strips of parchment cover the gap on the front face and/or on the reverse or the 

gap is filled with a paste of plant fibers or even rope.26 Applying 

caulk in the gap also seems to have been standard practice and is 

mentioned in ordinances. A typical feature in the construction of 

Valencian altarpieces seems to have been to fill up these narrow 

gaps with narrow wedges or fillets of wood called chuletas.

27 The 

joint of the Suermondt-Ludwig panel, St. John the Evangelist, is 

filled with these wedges, although the exteriors are missing, each 

measuring ~4 cm in length and a~0.4 cm in width (Figure 4). 

The wedges were usually hammered in from the front, with the 

narrowest part ending up at the reverse of the panel. The excess 

would be planed down at the front face prior to the application 

of the preparatory layers. Thus, this key piece of evidence made 

it possible to narrow down the origin of the panels to the northeastern coastal provinces of Spain. 

Indications of cross-board support also offer further insight 

into the original construction of the Suermondt-Ludwig retablo. Holes, placed in horizontal lines, are present in both panels, at roughly similar heights. Although these are clearly visible 

when observing the reverse of the St. John the Evangelist panel, 

X-radiography was required to determine the presence and positions of holes on the transferred panel.28 Damage in the paint 

and preparatory layers can clearly be distinguished. These holes 

result from nails, now removed, used to attach cross battens to 

the reverse of the panels. The travesaños (cross battens) were 

part of the original construction technique and are now missing. 

The position of the cross battens may also be indicative of a 

workshop or regional practice; however, with only traces that 

bear witness to these, it is not possible to draw further conclusions from this evidence. 

Often these battens were fastened, as is the case in these 

panels, with hand-forged iron nails inserted from the front and 

clinched at the reverse.29, 30 Remnants of an iron nail were found 

in one hole on the St. John the Evangelist panel; the others have 

been forcibly removed. The front of the support would have been 

planed smooth prior to the attachment of the cross battens, and 

the heads of the nails would have been countersunk into the flat 

surface. Larger constructions often had multiple battens distributed over the reverse. In Valencia, one pair of cross battens was 

typically placed diagonally in the shape of a St. Andrew’s cross 

(X), covering almost the entire height of the retablo. Furthermore, a series of additional horizontal cross battens was added, 

usually three or four. In Castile, a solely cross-grain, horizontal 

placement of the battens was more typical. Although the remnants in the original supports in this case point to a horizontal 

placement, a Valencian origin cannot be excluded on the basis of 

this factor alone since this one panel probably represents only a 

small fragment of a larger retablo and cruciform cross battens 

might have been present in other areas.31 Cross battens were attached to the reverse not only to reinforce the construction but 

also to aid in fixing the retablo to the wall of the church or chapel. Again, here, no evidence remains in the Suermondt-Ludwig 

panels to indicate how this was established.

TECHNICAL INVESTIGATION: NONINVASIVE 

AND MICROINVASIVE TECHNIQUES

Methods of Analysis

An investigation of the materials and techniques used to 

paint the panels focused on providing evidence to support or 

refute the hypothetical origin of the works as concluded from 

the structural examination described above. The budget for this 

phase of the investigation was limited. Thus, a select number of 

noninvasive and microinvasive methods for analysis were used 

that were available at SRAL or could be achieved under existing 

collaboration projects.32 Pigment analysis was carried out using 

cross-section samples using an analytical microscope and scanning electron microscopy-energy dispersive X-ray spectroscopy 

(SEM-EDS) linked with backscattered electrons (BSE) to identify 

the inorganic content. Where necessary, results were strengthened or corroborated using portable X-ray fluorescence (pXRF) 

in situ analysis.33 Fourier transform infrared spectroscopy–

attenuated total reflectance (FTIR-ATR), in combination with 

microchemical spot tests, was used to characterize the components of the ground material.34 Identification of the various binding media present in the decorative layers was not carried out 

because of the surface contamination by later additions, which 

included (oleoresinous) varnishes, waxes, and dirt. Analytical 

FIGURE 4. Detail of the reverse of St. John the Evangelist showing 

the wooden wedges, chuletas, one of which was temporarily taken 

out of the joint. Image: SRAL.
number 5 • 4 3

equipment to identify trace amounts of binding media was also 

not available. However, the use of multiple analytical techniques 

allowed a thorough examination and corroboration of results, 

determining the range of pigments used and confi rming painting 

technique. Conclusions were drawn by combining the information gained from all these techniques. 

RESULTS AND DISCUSSION

preparatOry layerS: preliMinary layerS anD GrOunD

The layer buildup used was confi rmed by examination of 

the surface using an optical light microscope and samples prepared as paint cross sections. The fi rst phase in preparing the 

panel for decoration could not be identifi ed in the samples; however, the researchers assume that this step was taken as it was 

standard practice. First, a layer of cola fuerte (hot animal glue) 

priming was applied to reduce the absorbency of the wood and 

provide good adherence for the subsequent layers. Often, the extract from boiled cloves of garlic was added to this glue. In this 

case the treatises call the glue a gíscola. The addition of garlic to 

this size layer was not investigated in the case of the SuermondtLudwig panels. Because it was well known that wooden supports 

“moved” after losing moisture content, the second step involved 

applying additional support over joints and knots to mitigate 

cracking in the layers applied subsequently. Materials included 

hemp fi bers and parchment scraps; in the case of the SuermondtLudwig panels the entire front face of the panel was covered 

with a fi ne (linen) canvas soaked in carpenter’s glue. The superimposed elements such as the carved wooden tracery present in 

both paintings examined here were added at this stage.35

The buildup of the subsequent decorative layers in the two 

panels studied is similar to the standard practice described by 

Francisco Pacheco (1564–1644).36, 37 Two ground layers consisting of gypsum bound in animal glue were applied over the entire surface of the panel previously covered by the linen canvas 

and superimposed tracery. Initial microchemical analysis, using 

an acidic solution of HCl, of scraping samples from the ground 

layers indicated that the ground contained gypsum (CaSO4

) 

rather than chalk (CaCO3

).38 The exact chemical nature of these 

samples was confi rmed using FTIR-ATR analysis and by EDS 

spot analysis on cross sections, described below. The FTIR-ATR 

spectra also showed peaks that indicated the presence of animal glue as a binder.39 Analytical techniques that would provide 

confi rmation of the binding media, such as gas chromatography 

mass spectrometry or high-performance liquid chromatography, 

were not carried out because of access and fi nancial restrictions. 

Cross sections examined with a light microscope showed that 

no pigments were added to the ground. This lack of colorant 

or pigments was confi rmed by the SEM-EDS analysis of a cross 

section taken from the blue cloak of St. John the Evangelist.40

This sample, when studied using the SEM-BSE mode, showed 

the particle morphology of each layer and revealed a remarkable 

difference in consistency between upper and lower ground layers 

(Figure 5). This difference of particle morphology confi rmed the 

application of two types of ground, the coarse yeso grueso and 

the fi ner yeso mate.41 The SEM-EDS analysis provided confi rmation of the presence of calcium and sulfur in the ground layer (see 

below). These materials and techniques are not exclusive to the 

coastal provinces of the Kingdom of Aragon or even the Iberian 

Peninsula, but they are typical of this region and period. The use 

of calcium sulfate as the constituent material for ground layers 

was commonplace in Valencia and Andalusia.42, 43 

FIGURE 5. A SEM-BSE image showing the layer buildup of the sample taken from the blue cloak of St. John the Evangelist. The ground is applied in two layers whose particle morphologies are clearly different. Image: SRAL.
4 4 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

Underdrawing and Incised Lines

The methods used for the decorative painting process 

also follow standard practice for this period and region as described in the sources previously referenced. In the case of the 

Suermondt-Ludwig panels, the composition was laid out on the 

smooth surface of the ground layer using two different techniques, ink and incision lines. The presence of an underdrawing 

in both paintings, made by the same hand, was confirmed using 

both IR digital photography and IR reflectography (IRR).44 A 

detailed plan of the composition was applied with brushes and 

possibly a stiffer (reed) pen using a dilute black medium. Application brushstrokes of varying widths and emphasis made 

by different drawing materials are visible in losses to the upper 

decorative layers, especially in the face of King Herod in the St. 

John the Baptist panel, and in the IRR reflectograms. The underdrawing delineates outlines of figures and architectural elements. Hatching was used to indicate shadows or modeling. The 

underdrawing is carried out meticulously by a skilled, confident 

draftsman. Although straight edges were used for the lines creating the architecture, the underdrawing of the figures and drapery 

is freehand. The underdrawing material was present in a number of cross sections removed from both paintings. Microscopic 

analysis of these cross sections identified a carbon-containing 

material. No color notations were found in the underdrawing 

phase as has been seen in other contemporary examples.45

The second method used in the initial outlay of the decorative scheme employed incised lines to delineate specific decorative elements. These lines can be seen clearly in raking light and 

in the X-radiographs. The incisions follow the outlines of areas 

designated for gilding (application of the bole) and the application of blue color.46 The incision channels were used to prevent 

the fluid medium (bole or pigment bound with animal glue) from 

flowing outside the designated area. Changes (arrepentimientos) 

in the initial decorative design become apparent when studying 

closely the overlay of paint application with the incision lines. 

Some areas, for instance, the windows in the background of St. 

John the Evangelist, were neither gilded nor painted blue. These 

arrepentimientos are few.

Again, here, the evidence gathered does not relate to a specific regional location but clearly correlates to artistic practice 

employed in the fifteenth century that is mentioned in contemporary Spanish sources. A study comparing the underdrawing 

style to those present in other contemporary panels could prove 

beneficial for the identification of a specific studio practice. 

Dorado (Gilding)

Metal leaf decorations were applied over a red bole layer, 

and gilded areas are delineated by incision lines. The bole and 

subsequent gilding were completed before painting. Different 

metals were used, depending upon the type of material depicted 

or spiritual significance of the image. Gold was used for the halos 

of the saints and the armor of one of the soldiers, whereas silver 

was found in the (steel/iron) helmets and weapons of the guards. 

The metal leaf application was subsequently painted or glazed 

to enhance the illusion of the metal depicted. Punch marks are 

present in the halos, armor, and background decorations—these 

were applied after the gilding. The metal was identified by elemental analysis using in situ pXRF spot analysis and on relevant 

cross sections using SEM-EDS. The metal leaf is also clearly visible in the cross sections from selected areas. 

As mentioned, most of the gilded areas were decorated using 

pigment bound in a sticky but fluid (oleoresinous) medium. The 

handling properties of this semitranslucent glaze are clearly visible at higher magnification. The edges of the colored glaze application are rounded, indicating a fluid application well past 

the no-flow point. The binding medium has not yet been identified, but its oleoresinous nature was concluded on the basis of 

visual appearance, UV fluorescence, and solubility characteristics. 

Again, here, the use of these colored glazes follows standard artistic practice for this period, not only for panel painting but also 

for the decoration of polychrome sculpture.47 These sgraffito and 

estofado techniques are applied to the surfaces of the gilded areas 

after the surrounding areas are painted. The effect creates a rich 

display of a variety of textiles and surfaces (Figure 6). However, 

many of these final decorative coatings on the Suermondt-Ludwig 

panels are reconstructions, although islands of original surface 

remain. These were deemed to be too sparse to use for sampling. 

Furthermore, later applications of varnish and other coatings, applied during previous restoration campaigns, have contaminated 

the original surface. It was felt that the later additions would confuse the interpretation of the results of any analysis carried out 

and thus did not justify sampling the scarce original material. 

Binding Media and Surface Appearance

Materials added over the centuries have altered the surface 

appearance of the panels. These additions also limited the opportunity for sampling the binding media used for the original 

paint. However, a study of the surface and the accompanying 

stylistic analysis was facilitated by conservation treatment that 

included the removal of varnish and overpaint layers. Observations were compared with standard painting practice as described by Pacheco and contemporaries. 

It was common fifteenth-century Spanish painting practice 

to combine tempera underpaints with oil glazes and pigmented 

oleoresinous coatings applied to gilded areas. The amalgamation of these surface finishes creates an interplay of painterly effects. The fine brushwork and application technique, especially 

in the faces, indicates the use of egg tempera, whereas the surface 

of the gilded draperies appears to have been created by glazing underpaint using an oil binding medium. Combining earlier paint technology with newer developments points toward a 

Hispano-Flemish influence within the workshop constructing the 

Suermondt-Ludwig panels.

Contemporaneous treatises suggest a proteinaceous binding medium would have been used for the azurite draperies, as 
number 5 • 4 5

this pigment did not perform well bound in oil, giving these a 

matte appearance.48 Unless these matte blue azurite applications 

were glazed with an oil-bound paint, it is likely that the matte 

effect was intentional, as was the silky glossy effect of the glazed 

gilding. Today, it is common knowledge that medieval tempera 

paintings were left unvarnished. That may have been the case 

for the surface of the Suermondt-Ludwig panels. The resulting 

surface would have been full of contrasts: partly brilliant and 

glittering, partly opaque and matte. The variation in surface effects is now lost because of past interventions and applications, 

including varnishes and other surface coatings.49

The combined use of egg tempera medium and oil glazing 

points to a Hispano-Flemish link. Strong links existed between 

the Low Countries and the Iberian Peninsula, sealed with a 

royal marriage between Philip the Good and Isabella of Portugal in 1430. Northern artists flocked to the south, bringing with 

them innovations in painting practice from the Low Countries. 

The binding medium used prior to the introduction of northern 

European techniques was predominantly egg tempera, utilized 

in a manner similar to that in the Italian peninsula. However, 

Flemish influence became dominant in Spain in the fifteenth century, and the introduction of oil-containing paints can be seen as 

a result of these cultural exchanges brought by artists arriving 

from the north. The combination of binding media is key to 

placing the Suermondt-Ludwig panels in a temporal context—

late fifteenth century. 

Paint Layers

Pigment analysis with pXRF was undertaken at several 

locations per color. Sites, where appropriate, were selected to 

correspond to cross-section sampling. Almost all the elements 

identified in the pXRF spectra can be linked to historic pigments that were used in the fifteenth century in Spain.50, 51 Table 

1 provides an overview of the elements found in the panel of St. 

John the Evangelist and the pigments they are associated with. 

Anomalies were found relating to elements typical for modern 

pigments, such as zinc. These clearly related to overpaints, and 

FIGURE 6. Detailed images showing different dorado techniques. Photograph taken during treatment after removal of upper varnish layer. 

Image: SRAL.
4 6 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

this evidence was discarded as this pigment use is anachronistic 

to the period in question. Other elements that can be linked to 

the use of modern paints were barium and sulfur (barium sulfide) 

and aluminum and silica (aluminum silicate), compounds often 

used as fillers in modern paints. Paints containing these materials 

clearly covered damaged original material. These areas were 

identified and confirmed with a close observation of the surface 

under magnification and in the corresponding cross sections. 

The outline, folds, and shadows of blue drapery have been 

demarcated with incised lines. In the Santa Marina retablo from 

Mayorga, investigated and treated in the late 1990s at the Hamilton Kerr Institute (HKI), something similar was observed.52 In 

this artwork, the blue draperies were also painted using an aqueous, proteinaceous medium. The pigment used was a very coarse 

azurite, and the color was applied in an even, flat layer. The folds 

and shading were indicated later, by painting hatching over the 

first flat layer of blue. Another remarkable find in the retablo 

treated at HKI was that there was a layer of black paint underneath the azurite layer. This layer gave the drapery a dark blue 

color when the azurite paint (with a low covering power due 

to the coarseness of the pigment particles) was applied over it. 

This technique made it possible to reduce the amount of azurite 

needed to create a rich blue paint and was thus an economical use of an expensive pigment. The black underpaint covered 

TABLE 1. Overview of pXRF measurements carried out on St. John the Evangelist. Similar measurements were also found for St. John 

the Baptist. The condition of the original paint layers is much worse than on St. John the Evangelist (photograph taken during treatment). Much of this surface has been heavily repainted with paints containing zinc. The measurements here are thus not conclusive.

No. Color Elements detected Pigment used

1 White Pb, Ca Lead white

2 Pb, Ca Lead white

3 Black Pb, Ca, Sr, Fe, P Bone black

4 Blue Cu, Ca, Sr, Fe, Pb Azurite

5 Blue Cu, Ca, Ba, S, Zn, 

Sr, Pb, Al, Si

(Modern) azurite with zinc oxide and 

barium sulfide fillers

6 Blue Cu, Zn, Ba, Fe, Ca, 

Al, Si, S, Pb

(Modern) azurite with zinc oxide and 

barium sulfide fillers

7 Blue Cu, Zn, Ba, Fe, Ca, 

Al, Si, S, Pb

(Modern) azurite with aluminum silicate and barium sulfide fillers

8 Green Zn, Pb, Fe, Ca, P, 

Al, Si

(Modern) green paint with copper-based 

pigment and aluminum silicate extender

9 Red Pb, Sr, Ca, Al Red lake pigment

10 Red Pb, Ca, Sr, Hg Vermillion

11 Metal leaf Ag, Pb, Ca, Sr, P Silver leaf with earth pigments applied 

on top

12 Metal leaf Au, Fe, Ca, Sr, Pb Gold leaf, possibly glazed with ochres

13 Metal leaf Ag, Pb, Ca, Sr, Fe, 

Cu

Silver leaf with earth pigments applied 

on top

14 Gray Pb, Fe, Ca, Sr, P Lead white with very little bone black 

(weak phosphorous peak)

15 Flesh tone Pb, Hg, Ca, Sr, Fe Lead white mixed with vermillion

16 Brown Pb, Fe, Ca, Sr, Zn Lead white, earth pigments, and zinccontaining overpaint

17 Flesh tone Pb, Ca, Sr, Hg Lead white mixed with vermillion

18 Green Cu, Pb, Ca, Sr, Fe Copper-based green such as malachite, 

verdigris, or copper resinate

19 Yellow Pb, Ca, Sr, Fe, Lead white and earth pigments

20 Purple Pb, Ca, Sr Possibly lake pigment

21 Brown Pb, Fe, Ca, Sr, Zn Lead white, earth pigments, and zinccontaining overpaint

22 Yellow Pb, Fe, Ca, Sr Ochre

23 Red brocade Au, Hg, Ca, Sr Vermillion on gold leaf
number 5 • 4 7

the underdrawing, necessitating the use of incised lines to indicate shapes and folds.53 However, no such black underlayer was 

found in the Suermondt-Ludwig panels. 

A cross section from the blue drapery of the seated priest in 

the panel of St. John the Evangelist shows a ground applied in 

two layers, a thin black layer (directly related to the ink underdrawing) and an upper layer of coarse azurite. Remnants of additional layers containing ultramarine are present (likely from an 

early overpaint application). They are difficult to observe in the 

cross section using the analytical microscope but can be clearly 

observed on the surface. 

To gain further understanding of the abovementioned crosssection sample, elemental mapping and false-color imaging were 

carried out using SEM-EDS (Figure 7). Results showed the presence of the element copper in the undermost paint layer, imaged 

in blue. The element silicon (colored yellow) is present in the same 

layer as the copper. Silicon is indicative of silica and/or quartz; both 

minerals are associated with natural copper mineral compounds 

such as azurite and lapis lazuli. However, the morphology of the 

particles containing copper indicates azurite (2CuCO·Cu(OH)2

) 

as opposed to ultramarine ((Na,Ca)8

(AlSiO4)

6

(S,SO4,Cl)1-2). Elemental calcium is mapped in light blue in this cross section, 

whereas the element sulfur is mapped in pink. Both elements are 

present in both ground layers. This result is suggestive of the use of 

calcium sulfate (CaSO4

), confirming the findings of the previously 

mentioned microchemical tests. Calcium is also mapped above the 

azurite-containing layer, which may be associated with the filling 

material applied to repair damage adjacent to the sampled area. 

The absence of sulfur in the mapping of this layer suggests the use 

of calcium carbonate for the fill, which was confirmed by a microchemical analysis of the filling material. The remnants of an ultramarine glaze (possibly in an oil medium) applied over the azurite 

layer were visible using light microscopy of the area where the 

sample was taken. However, elements associated with this mineral 

pigment, such as sodium and aluminum were not mapped in this 

cross section. It is possible that the sample was removed from an 

area that did not contain this pigment. No intermediate varnish 

layers were observed in this sample. The authors hypothesize that 

the blue drapery was painted using a copper-containing pigment, 

probably azurite, that was later covered with a paint containing 

ultramarine. Different binding media were used for the different 

layers. 

The cross-section analysis did not help the authors in determining the originality of the upper, now damaged, ultramarine oil paint. This paint has been applied over all of the blue 

draperies covering the azurite paint on both panels. The binding 

medium of this layer is unconfirmed, but it has the appearance 

under magnification of an oil paint as opposed to tempera.54 One 

FIGURE 7. Composite showing sample site. Combined false-color SEM-EDS backscatter image with superimposed elemental mapping (left) 

and SEM-EDS elemental maps for silicon, sulfur, calcium, and copper. Image: SRAL.
4 8 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

hypothesis is that the original matte blue azurite paint was glazed 

with an oil-bound ultramarine paint as part of the original painting technique. However, this would negate the supposition that 

the overall surface appearance was intended to use contrasting 

textures of matte and gloss. The opposing, perhaps more likely, 

argument would be that the ultramarine layers were an early 

restoration applied to cover damage to the water-sensitive proteinous bound azurite layers. These layers are severely damaged 

and only partially preserved. Interpretations of the layer buildup 

and originality of materials are complicated as the ultramarinecontaining layers are also severely damaged. Furthermore, many 

of these areas were also covered by additional overpaints before 

the current conservation treatment. Undercutting resulting from 

later cleaning campaigns of all layers has also been identified. 

The authors are aware that additional research is necessary to 

confirm the hypotheses proposed here but feel that it is appropriate to discuss this tentative technological finding with a wider 

audience. 

STYLISTIC ATTRIBUTION

It is not the intention of this paper to provide an attribution 

of the Suermondt-Ludwig panels to a particular artist or workshop. However, there is a close stylistic resemblance between the 

Suermondt-Ludwig paintings and that of Jaume Huguet (1412–

1492), who was recorded as working in Barcelona. The similarities are striking, in particular in relation to the different hats worn 

by the figures. Also working in similar style was Juan Reixach 

(active 1431–1482), active in Valencia and Catalonia. Further 

comparisons could be made with other works in the 2006 exhibition catalog Greco, Velázquez, Goya from the Museum of Fine 

Arts Budapest that could substantiate the hypothesis here.55, 56

CONCLUSION

Contemporary Spanish painting techniques are clearly described elsewhere, most famously by Pacheco, and although 

writing around 150 years later, many of the practices he describes can be applied to fifteenth-century artworks. Medieval 

artists-craftsmen were working in a controlled mass production 

market; each phase of the construction and decoration process 

was carefully regulated by ordinances, statutes, and contracts. 

The Suermondt-Ludwig panels conform to these norms. 

The systematic study of the artworks, using both nondestructive and microdestructive analytical techniques, provided conservators with sufficient information to facilitate the decision-making 

process for treatment options. The poor condition of the works 

was evident on initial examination, which initiated the materialtechnical study. The investigation aimed to provide information 

to inform strategies for treatment that are reported elsewhere.57

Evidence of the materials and construction techniques used in the 

panels has highlighted the rarity of similar artworks in German 

collections and has thus placed a greater emphasis on the current 

investigation and conservation treatment. Preserving the original 

materials without altering their nature has become paramount. 

The insect-damaged support will be maintained and stabilized. 

Future aesthetic treatment will involve the removal of nonoriginal 

paint layers, identified in this study. 

This study provided considerable information about the 

original materials used to construct the panels and their physical 

history. Combining the hard facts resulting from the materialtechnical study with more theoretical discussions regarding the 

iconography and fifteenth-century Spanish painting practice 

specific to Catalonia or the province of Valencia allowed the 

authors to contextualize the results of both studies. Uniting conjectural hypotheses with factual data has enabled conclusions to 

be drawn. It can be concluded that both panels were once part 

of a much larger whole. The presence of wooden chuletas means 

that a more specific origin can be pinpointed. This construction 

technique is typical of Catalonia or Valencia, regions that were 

part of the Crown of Aragon in the fifteenth century. Establishing a clearer provenance for the panels would perhaps reveal the 

location of other sections of the altarpiece and even the exact 

church for which this retablo was constructed. This investigation 

still needs to be carried out. However, taking into consideration 

local historical events, it is possible that the panels were removed 

from their original setting in the church and dismembered for 

sale on the art market prior to or in the early nineteenth century. 

That would explain the change in dimension and partially elucidate their current condition. It should be stressed that there is, to 

date, no archival evidence supporting this assumption. 

Acknowledgments

The authors thank Luis Bertomeu Contreras (Universitat Politècnica de València), Luuk Hoogstede (SRAL), Arnold 

Truyen (SRAL), and Paul van Kan (consultant SRAL and Van 

Kan & Willems). The authors give special thanks to Britta New 

(The National Gallery, London) for her strategizing and advice 

with regard to decision making for treatment. Additional thanks 

go to all experts who have contributed in expanding the understanding of Spanish painting techniques of the authors, in particular Guillermo Torres Llopis (Esconres, Huesca, Aragon) and 

Ana Calvo (Universidad Complutense de Madrid). 

The conservation team has included Marya Albrecht, 

Melissa Daugherty, Lieve d’Hont, Femke van Gurp, Jazzy de 

Groot, and Diana de Man—all participating in various stages 

during their yearlong residency at SRAL, under the supervision 

of Kate Seymour, as part of their postgraduate training at the 

University of Amsterdam. Ray Marchant (HKI) has consulted 

on the structural treatment of the St. John the Evangelist panel, 

and his knowledge of fifteenth-century Spanish construction 

techniques was key to interpreting the complexities of this project. The project is ongoing at the time of press. The project has 

been facilitated by Michael Rief and the team at the SuermondtLudwig-Museum in Aachen. The National Science Foundation 
number 5 • 4 9

is gratefully acknowledged for two grants for nondestructive instrumentation at Washington and Lee University (W&L; NSF 

MRI CHE-0959625 and CHE-1337481). The Lenfest Summer 

Grant program at W&L is gratefully acknowledged for funding 

Erich S. Uffelman’s travels to The Netherlands with the pXRF. 

The team is most grateful for these contributions. 

NOTES

1. This paper was originally presented at the International Council of Museums–Committee for Conservation interim meeting “The Non-Invasive Analysis of Painted Surfaces: Scientific Impact and Conservation Practice” held 

at the Lunder Conservation Center in February 2014 under the title “CSI 

Aachen: Unraveling the History of Two Fifteenth Century Spanish Panels 

Using Forensic Methodologies.”

2. The two panel paintings are registered under the titles St. John the Evangelist 

Drinking from the Poisoned Chalice (GK84a) and The Beheading of St. John 

the Baptist and the Feast of Herod (GK84b), Suermondt-Ludwig-Museum, 

Aachen. Throughout this paper they will be referred to as St. John the Evangelist and St. John the Baptist.

3. Little information has come to light regarding Louis (Ludwig) Beissel. His 

father, also called Ludwig, was a founding member of the Firmierung DrahtFabrik-Compagnie in Aachen, along with Johann Friedrich Thyssen (1804–

1877). Thyssen is an ancestor of Baron Hans Heinrich Thyssen-Bornemisza, 

who bequeathed his art collection to the Spanish government in 1993; the 

collection is now on display at the Thyssen-Bornemisza Museum in Madrid. 

This link needs further investigation.

4. Archival documentation folders associated with GK84a+b of the SuermondtLudwig-Museum, Aachen, Germany, accessed June 2012.

5. The 1914 documentation folder from the Suermondt-Ludwig-Museum Archives states, “zwei altarflügel in einen Rahmen. Szenes aus dem Leben der 

beiden Johannes. Burgundisch (?) XV. Jahrhundert.” 

6. E. Nyerges, El Greco, Velázquez, Goya: Five Centuries of Spanish Masterpieces (Budapest: Museum of Fine Arts, 2006), 42–43.

7. Matthew 14:1–12, consulted at Biblia.com, http://biblia.com/bible/esv/Mt

%2014.1-12 (accessed 2 June 2015).

8. The Acts of John is an early second-century Christian collection of Johannine 

narratives and traditions, long known in fragmentary form. The traditional 

author was said to be Leucius Charinus, a companion and disciple of John. 

M. R. Jones, trans., The Apocryphal New Testament (Oxford: Clarendon 

Press, 1924), sections 94–96, http://gnosis.org/library/actjohn.htm (accessed 

2 June 2015).

9. The frame is no longer in existence and is probably a nineteenth-century 

faithful stylistic copy. The intact condition of the pinnacles is discordant with 

the age, some 500 years, and the damaged condition of the panel paintings.

10. J. Hall, Dictionary of Subjects and Symbols in Art, rev. ed. (New York: 

Harper & Row, 1979).

11. From the beginning of the twelfth until the early eighteenth century, the Crown 

of Aragon was a thalassocratic Mediterranean state, consisting of the modernday Spanish provinces of Aragon, Catalonia, and Valencia, as well as territories 

held in Italy and Greece, including the Balearic Islands, Corsica, Sardinia, and 

Sicily. Zaragoza was the political center in the fourteenth and fifteenth centuries. Cultural exchange and influence from these territories dominated artistic 

development in Spain prior to the later medieval Flemish connections.

12. J. Berg-Sobre, “Two Fifteenth-Century Aragonese Retables and Painters of 

the Calatayud Group,” Metropolitan Museum Journal 15 (1980): 91–118.

13. Bernat Martorell, Retaule dels sants Joans, inventory no. 064045-CJT, Museu Nacional d’Art de Catalunya, http://www.museunacional.cat/ca/colleccio

/retaule-dels-sants-joans/bernat-martorell/064045-cjt (accessed 2 June 15); 

Bernat Martorell, St. John the Evangelist Drinking from the Poisoned Chalice, Musee Rolin, Autun, France. Dated ca. 1435–1445. Dimensions 344 × 

261.5 × 10.5 cm.

14. The terminology of Spanish altarpieces is described in F. Descamps, Methodology for the Conservation of Polychromed Wooden Altarpieces (Seville, 

Spain: Consejería de Cultura, 2002), and the resulting online resource, Getty 

Conservation Institute and Instituto Andaluz del Patrimonio Histórico, “Altarpieces: Illustrated Basic Terminology,” http://www.gciresources.org/retablo

/index2.php?id=2 (accessed 2 June 2015). The central section of the altarpiece 

(retablo) is termed banco, the lateral columns are called calles, the upper portion is called ático, and the lower section is termed sotto banco. The definitions for other terms are given in the text.

15. There is no documentation relating to this treatment. The only existing reference is an article from the local newspaper Aachener Nachrichten (no. 293, 

23 December 1978), a photocopy of which is kept in the documentation 

folder for GK84a+b in the Suermondt-Ludwig-Museum SLM archives. The 

article describes the work of restorer Helmut Weirich (now deceased); the 

photograph accompanying the article shows the restorer retouching the panel 

of St. John the Evangelist. By comparing this photograph with the current 

state of the panel it became clear that the panel was already transferred to 

a new support at that time. Helmut Weirich most probably carried out the 

treatment shortly before the photograph was taken.

16. Wood species analysis was carried out by Peter Klein (then University of 

Hamburg, Germany) in 1995 and was identified as pinewood. Archival documentation folder for GK84a+b of the Suermondt-Ludwig-Museum, accessed 

June 2012.

17. Wood samples, frass, and insect remains were examined by Jos Creemers 

from SHR (http://www.SHR.nl). He identified the presence of two xylophagous species of insects: a beetle deriving from the Anobiidae family, given the 

diameter of the galleries and the shape of the fecal pellets, and a beetle from 

the Nicobium genus, based on the presence of a cocoon.

18. Construction of churches and similar edifices was rampant in fifteenthcentury Spain. As the Moors were pushed out of the country, the reassertion 

of the Christian faith led to the mass construction of new churches and decorations for these interiors.

19. A. Calvo Manuel, “Retablos Medievales del Norte Valencia,” in Retablos: 

Técnicas, materiales y procedimientos (Madrid: Grupo Español IIC, 2004), 

6, http://ge-iic.com/files/RetablosValencia/anacalvoRetablosnortevalenciano

.pdf (accessed 2 June 2015).

20. Guilermo Torres Llopis, Escuela Superior de Conservación y Restauración 

de Bienes Bulturales de Aragon, personal communication with the authors, 

16 February 2014.

21. C. Fava Monllau, “El Calvario cuatrocentista catalán del Museo de Bellas 

Artes de Bilbao,” Boletín del Museo de Bellas Artes de Bilbao 8 (2014): 47–83. 

22. R. Bruquetas Galan, “Los gremios, las ordenanzas, los obradores,” in Retablos: Técnicas, materiales y procedimientos (Madrid: Grupo Español IIC, 

2004), 7, http://ge-iic.com/files/RetablosValencia/R_Bruquetas.pdf (accessed 

2 June 2015).

23. At least two dowels are required along the length of a joint to achieve correct 

alignment.

24. A. Nualart i Torroja, M. Mascarella Vilageliu, and I. Bautista Morenilla, “Frontals d’altar medievals: Marques d’eines a la fusta i tecnologia de construcció 

del support,” In La Recerca en Conservació des de la Visió del ConservadorRestaurador II. Setmana de la Ciència, Barcelona, 20 i 21 de novembre de 

2014 (Barcelona: Secció de Conservació-Restauració, Facultat de Belles Arts, 

Universitat de Barcelona, 2014), 29–36, http://diposit.ub.edu/dspace/bitstream

/2445/60507/1/3RCRII_Nualart%20et%20al.pdf (accessed 2 June 2015).

25. A. Carrassón López de Letona, “Construcción y ensamblaje de los retablos 

en madera,” in Retablos: Técnicas, materiales y procedimientos (Valencia: 

Grupo Español IIC, 2004), 3–4, http://www.ge-iic.com/files/RetablosValencia

/AnaC_Construccion_ensamblaje.pdf (accessed February 2015).

26. Bruquetas Galan, “Los gremios, las ordenanzas, los obradores,” 8; S. Hodge, 

M. Spring, and R. Marchant, “The Santa Marina Retable from Mayorga, 

Attributed to the Master of Palanquinos, c.1490’s,” Hamilton Kerr Institute 

Bulletin 3 (2000): 7–40.

27. Calvo Manuel, “Retablos medievales del Norte Valencia,” 6–7.

28. X-radiographies were carried out by Arnold Truyen (SRAL) using ERESCO 

160 MFR2 industrial X-ray equipment. The range of the tube is 200 kV, but 

energies over 99.99 kV are blocked. Settings used to acquire optimum contrast are available on request.

29. V. Vivancos Ramón, “Aspectos técnicos y estructurales de la retablística Valenciana,” in Retablos: Técnicas, materiales y procedimientos (Madrid: Grupo 

Español IIC, 2004), 6, http://ge-iic.com/files/RetablosValencia/V_Vivancos

_ATyEstructurales.pdf (accessed 2 June 2015).

30. An undecorated fifteenth-century panel support using the described technique can be found in the Conservation Studio of the Museo Nacional del 

Prado, Madrid.

31. Calvo Manuel, “Retablos medievales del Norte Valencia,” 6.

32. A fruitful collaboration for technical analysis exists between SRAL (Maastricht, Netherlands) and Washington and Lee University (Lexington, Virginia, 

USA). This ongoing collaboration brings coauthor Erich S. Uffelman, along 
5 0 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

with a range of portable analytical equipment, to The Netherlands on an 

almost yearly basis. Details of the techniques and equipment used under the 

auspices of this collaboration are given throughout the rest of this paper.

33. All measurements were carried out by Erich S. Uffelman (Washington and 

Lee University) using a Bruker Tracer III-SD, Rh anode X-ray tube at 40 kV 

and 11 μA, 20 Torr interior pressure inside the instrument, 180 s spectrum 

accumulation time, 2,048 channels. The spot size analyzed consisted of a 4 

× 6 mm oval. The front of the instrument was carefully placed parallel to the 

picture plane. Great care was used to position the instrument safely (using 

a tripod with a manually controlled, geared instrument mount) within approximately 1 mm of the painting surface. The element assignments were 

made using the Bruker Artax 7.2.1.1 software, but comprehensive tables of 

XRF lines are readily available in common sources. 

34. Cross-section samples were embedded in Polypol (polyester resin). The embedded samples were sanded wet and dry polished using Micromesh. The 

samples were carbon coated for SEM-EDX analysis. Scraping samples were 

used for FTIR-ATR and microchemical tests.

35. Vivancos Ramón, “Aspectos técnicos,” 7.

36. F. Pacheco, Arte de la pintura (1641), 2nd ed. (Madrid: Manuel Galiano, 

1866), https://books.google.nl/books?id=IitPAAAAYAAJ&printsec=front

cover&hl=nl&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false 

(accessed 2 June 2015).

37. Z. Véliz, “Pacheco’s Comments on Painting in Oil,” Studies in Conservation

27, no. 2 (1982): 49–57.

38. A microchemical spot test was carried out to determine whether chalk 

(CaCO3

) or gypsum (CaSO4) was used in the ground and for the filling previously inserted along the open joint. A scraping sample was taken of both 

ground and filling. When a carbonate (CO3

2−) comes into contact with an 

acid, CO2

 is released, which can be seen under magnification as small bubbles 

appearing in the liquid. This technique is not precise but provided a first step 

in the analytical protocol used to investigate these panels. Both scrapings 

were mounted on a glass microscope slide, and a few drops of HCl were 

added while the slides were examined under the microscope. The sample 

from the ground did not react, which indicates the presence of gypsum. The 

sample from the fillings did show the formation of bubbles, indicating the 

presence of a carbonate. The exact nature of the gypsum mineral and its related water content were not confirmed with this method, nor was the exact 

nature of the carbonate. The white fill is radio-opaque and thus is likely to 

contain a lead white pigment component.

39. The FTIR analysis was carried out on a Bio-Rad FTS-6000 equipped with a 

Pike Gladi ATR setup. Spectra were controlled by WinIR Pro software and 

compared to standards in the Infrared Users Group (IRUG) database. The 

spectrum of the analyzed sample shows stretching vibration bands at 1,200–

1,050 and 680–600 cm−1. The analysis was carried out by Paul van Kan (a 

consultant for SRAL).

40. The SEM-EDS analysis was carried out on a JEOL JSM-5800 equipped with 

an Oxford INCA X-act EDS system with a Solid State Data (SSD) detector 

controlled by Oxford AZTEC software. The analysis was carried out by Paul 

van Kan (a consultant for SRAL).

41. Véliz, “Pacheco’s Comments on Painting in Oil,” 50.

42. Z. Véliz, “Wooden Panels and Their Preparation for Painting from the Middle Ages to the Seventeenth Century in Spain,” in The Structural Conservation of Panel Paintings: Proceedings of the Symposium at the J. Paul Getty 

Museum 1995 (Los Angeles: J. Paul Getty Museum, 1995), 136–148.

43. A. Rodríguez-López, N. Khandekar, G. Gates, and R. Newman, “Materials 

and Techniques of a Spanish Renaissance Panel Painting,” Studies in Conservation 52 (2007): 81–100.

44. Infrared digital imaging was performed with an XNite Lumix LX5 

UV+VIS+IR camera obtained from MaxMax that had the IR blocking filter 

removed. A filter adapter was attached to the front of the camera, and images 

were taken using either a filter that blocked ultraviolet-visible (UV-VIS) and 

IR electromagnetic radiation up to 715 nm or a filter that blocked UV-VIS 

and IR electromagnetic radiation up to 1,000 nm. Both filters were also obtained from MaxMax. Given that the camera’s silicon-based detector cuts off 

around 1,050 nm, the imaging windows were thus about 715–1,050 nm or 

1,000–1,050 nm. The camera was part of the equipment brought to SRAL by 

Erich S. Uffelman (Washington and Lee University, Virginia, USA). The IRR 

reflectography was carried out with the Hamamatsu Vidicon camera present 

at SRAL. Vidicon has a PbS photoconductive detector and has a resolution 

of 768 × 576 pixels for Pal or 640 × 480 pixels for NTSC. Vidicon cameras 

are sensitive from ~800 to 2,200 nm, with a maximum (optimal) response at 

around 1,900 nm. The UV-VIS radiation was eliminated using appropriate 

filters. Images were snatched from the live feed and stitched together by hand 

using Adobe Photoshop software.

45. C. Barry, “Observations on Workshop Practice in 15th Century Castile: The 

Altarpiece from the Cathedral at Ciudad Rodrigo by Fernando Gallego and 

His Workshop,” in Studying Old Master Paintings: Technology and Practice,

ed. M. Spring (London: Archetype, 2011), 295–301.

46. The incised lines would prevent the more fluid bole and blue paint from 

bleeding into adjacent areas that would receive other colors, thus preventing 

any chromatic interference with any overlying color.

47. It should be remarked that the artisans painting the panel paintings were the 

same as those applying the decorative layers on polychrome sculptures in this 

historical period.

48. The binding medium of the blue paint applications has yet to be confirmed by 

any instrumental analysis but follows standard medieval practice discussed. 

All blue areas on the panels have suffered severe damage in past cleaning 

campaigns, underlining the use of a proteinaceous binding medium. The majority of these areas are heavily overpainted, which makes the interpretation 

of original layers difficult.

49. The authors are aware that this hypothesis is unconfirmed through analysis. 

This type of connoisseurship, when taken in context with other evidence, can 

provide reliable conclusions that are far more than assumptions.

50. A. Križnar, V. Munoz, F. De la Paz, M. Respaldiza, and M. Vega, “Portable 

XRF Study of Pigments Applied in Juan Hispalense’s 15th Century Panel 

Painting,” X-ray Spectrometry 40 (2011): 96–100, http://dx.doi.org/10.1002

/xrs.1314.

51. Rodríguez-López et al., “Materials and Techniques,” 81–100.

52. Hodge et al., “The Santa Marina Retable,” 7–40.

53. M. Spring, “The Technique and Materials of the Blue Draperies,” Hamilton 

Kerr Institute Bulletin 3 (2000): 24–25.

54. The saturation of the layer and the handling of the paint indicate oil rather 

than a protein layer.

55. Nyerges, El Greco, Velázquez, Goya, 42–43.

56. Fava Monllau, “El Calvario cuatrocentista,” 47–83.

57. K. Seymour, M. Albrecht, M. Daugherty, S. Van Oudheusden, L. d’Hont, M. Rief, 

and R. Marchant, “The Thin End of the Wedge: Stabilisation of a Damaged Panel 

Painting Support Using Tapered Wooden Sections,” In ICOM-CC 17th Triennial 

Conference Preprints, Melbourne, 15–19 September 2014, ed. J. Bridgland (Paris: 

International Council of Museums Art, 2014), article 1312.

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Panel Painting Support Using Tapered Wooden Sections.” In ICOM-CC 

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J. Bridgland, article 1312. Paris: International Council of Museums Art, 2014.

Spring, M. “The Technique and Materials of the Blue Draperies.” Hamilton Kerr 

Institute Bulletin 3 (2000): 24–25.

Suermondt-Ludwig-Museum. Archival documentation folder pertaining to 

GK84a+b Suermondt-Ludwig-Museum, Aachen, Germany.

Véliz, Z. “Pacheco’s Comments on Painting in Oil.” Studies in Conservation 27, 

no. 2 (1982): 49–57.

———. “Wooden Panels and Their Preparation for Painting from the Middle Ages 

to the Seventeenth Century in Spain.” In The Structural Conservation of 

Panel Paintings: Proceedings of the Symposium at the J. Paul Getty Museum 

1995, ed. K. Dardes and A. Rothe, pp. 136–148. Los Angeles: J. Paul Getty 

Museum, 1995.

Vivancos Ramón, V. “Aspectos técnicos y estructurales de la retablística Valenciana.” In Retablos: Técnicas, materiales y procedimientos. Madrid: Grupo 

Español IIC, 2004. http://ge-iic.com/files/RetablosValencia/V_Vivancos

_ATyEstructurales.pdf (accessed 2 June 2015).

ABSTRACT. The identification of altered cadmium yellow paints in early modernist works is critical to their stabilization and to the long-term preservation of the paintings in which they occur. The 

identification of incipient photoalteration of these pigments, before there is visual evidence of their 

chemical degradation, is of particular concern. The alteration of these pigments causes chalking, 

flaking, fading, and darkening of the yellow paints, leading to irreversible changes in the physical 

and chemical structure of the paint layer and dramatically altering the appearance of the work. 

Standoff methods for the identification of this phenomenon are desired to rapidly and efficiently 

survey the condition of the pigment across an entire work and also to minimize invasive and destructive analyses wherever possible. Such methods are a particular need for collections with large 

holdings of Impressionist and early modernist works from the 1880s to the 1920s, for which these 

cadmium yellow alterations are particularly problematic and a rapid surveying method for the 

collection is needed. To address this challenge, four standoff methods were attempted (both alone 

and in concert): ultraviolet-induced visible fluorescence, ultraviolet-induced infrared fluorescence, 

multispectral imaging, and X-ray fluorescence. Questions addressed included the following: Is the 

imaging method being tested comprehensive? Is it efficient at surveying an entire painting? Does it 

reveal the state of preservation of the pigment? Does it reliably discriminate among intact versus 

altered cadmium yellow pigments? To answer these questions, the methods were tested on Henri 

Matisse’s Le Bonheur de vivre (1905–1906, the Barnes Foundation, Philadelphia) and oil sketches 

for this work in the San Francisco Museum of Modern Art and the Statens Museum for Kunst, 

Copenhagen. They were also tested on Edvard Munch’s The Scream (ca. 1910?, Munch Museum, 

Oslo). It was found that ultraviolet-induced visible fluorescence has the best ability to discriminate 

between altered and unaltered cadmium yellow paints (even before alteration is visible to the unaided eye), whereas multispectral imaging allows for the most efficient and comprehensive localization of the cadmium pigments in a work. 

1

 University of Delaware, Department of Chemistry and Biochemistry, 5105 Kennett Pike, Winterthur, Delaware 19735, USA.

2

 Department of Chemistry, Science Addition 

A427, Washington and Lee University, Lexington, Virginia 24450, USA.

3

 Barnes Foundation, 2025 Benjamin Franklin 

Parkway, Philadelphia, Pennsylvania 19130, USA. 

4

 Munch Museum, Tøyengata 53, 0578 Oslo, 

Norway.

5

 CATS and Statens Museum for Kunst, 

Sølvgade 48-50, 1307, Copenhagen, Denmark.

6

 Department of Chemistry and Biochemistry 

University of Delaware, Newark, Delaware 

19716, USA.

7

 Conservation Division, National Gallery of 

Art, 2000B South Club Drive, Landover, Maryland 20785, USA.

* Correspondence: J. Mass, jmass@udel.edu

Manuscript received 21 February 2015; accepted 22 February 2016.

Portable X-ray Fluorescence and 

Infrared Fluorescence Imaging Studies 

of Cadmium Yellow Alteration in Paintings 

by Edvard Munch and Henri Matisse 

in Oslo, Copenhagen, and San Francisco 

Jennifer Mass,1* Erich Uffelman,2 Barbara Buckley,3 Inger 

Grimstad,4

 Anna Vila,5 John Delaney,7 Jorgen Wadum,5 Victoria 

Andrews,2

 Lindsay Burns,2 Samuel Florescu,2 and Alyssa Hull6
5 4 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

INTRODUCTION

Cadmium Yellow Alteration in Works

of the Early Modernists

The synthetic inorganic pigments of the early modernist 

paintings from the turn of the twentieth century are undergoing 

chemical and physical degradation phenomena ranging from 

fading and color shifts to flaking and spalling (the breaking off 

of larger fragments). These phenomena have been particularly 

notable in the yellow pigments popular in this time period, with 

discoloration of zinc yellow (K2

O·4ZnCrO4·3H2O), chrome 

yellow (PbCrO4

), and cadmium yellow (CdS) paints being observed in the works of Georges Seurat (zinc yellow and cadmium yellow), Vincent van Gogh (chrome yellow and cadmium 

yellow), and Pablo Picasso (cadmium yellow; Casadio et al., 

2011; Leone et al., 2005; Van der Snickt et al., 2012). Since the 

late nineteenth century cadmium yellow paints (in particular, 

the paler shades) have been observed to undergo disfiguring 

fading and discoloration (Church, 1890), and the phenomenon 

has been noted in the art conservation literature since 1986 

(Fiedler and Bayard, 1986). At the time, this deterioration was 

attributed to either adulterants in the paint formulation or to 

the smaller particle sizes (and hence higher surface areas) of 

the paler shades. In conjunction with the fading and discoloration that one often observes, an irreversible degradation 

of the oil paint binder results in a chalky, crumbling, flaking, 

and, ultimately, spalling paint layer—this degradation proceeds 

from the exterior to the interior of the paint layer (Mass et al., 

2013a). Leone et al. (2005) performed the first systematic study 

of the alteration of cadmium yellow pigments, including the 

characterization of 12 works from 1887 to 1923, encompassing those by Vincent van Gogh, Pablo Picasso, Georges Seurat, 

and Fernand Leger. Notably, amorphous or nanocrystalline 

CdS was identified in 7 of the 12 paintings (based upon the 

absence of X-ray diffraction patterns). Potential CdS photodegradation products identified in the paintings included cadmium 

carbonate (CdCO3

), cadmium oxide hydroxide, cadmium carbonate oxide, and cadmium sulfate (CdSO4

). It is important 

to note that CdCO3

 and CdSO4 are both reagents for the wet 

process syntheses of CdS, so their identification alone does not 

constitute conclusive proof of photooxidation (Mass et al., 

2013b; Plahter and Topalova-Casadiego, 2011). However, the 

identification of these phases at the paint’s surface as discolored 

degradation crusts can suggest that they were produced by a 

photooxidation mechanism. Artificial aging experiments on period cadmium yellow paints were also carried out by Leone et 

al. (2005) at 45% relative humidity (RH) and 85% RH. The 

samples aged under high-RH conditions were noted to have a 

matte or etched appearance, and time-of-flight secondary ion 

mass spectrometry analysis revealed a lower concentration of 

fatty acids at the degraded surface, suggesting that the paint 

binding medium is being attacked during the degradation 

process (Leone et al., 2005). This led the researchers to propose a mechanism in which amorphous or nanocrystalline 

(and thus reactive) CdS pigment was photooxidized to produce 

CdO, CdSO4

, and SO2 gas. Van der Snickt et al. (2009) have 

observed the formation of CdSO4

·2H2O and [NH4]2Cd(SO4)2

on the surface of faded cadmium yellow paints in the works 

of James Ensor (1860–1949). n-X-ray absorption near edge 

spectroscopy was used in the Ensor study to demonstrate that 

the sulfur in the CdS was oxidized to SO4

2−, and it was hypothesized that the soluble cadmium sulfate was reprecipitating at 

the surface of the painting to form the observed white globules 

on the yellow paint layer. The ammonium phase was ascribed 

to a potential reaction with a previous cleaning treatment. This 

study also notes that a characteristic ultraviolet-induced orange fluorescence for the CdS is observed only in regions of 

the painting not blocked by the frame, so the authors associate this fluorescence with the photodegradation process, noting 

that the CdS yellow blocked by the frame appears brown under 

UV illumination. 

Cadmium Yellow Alteration in Works

by Henri Matisse and Edvard Munch

Le Bonheur de vivre (Figure 1) is considered to be one of 

the icons of modern art, responsible for cementing Matisse’s 

reputation as an innovative Fauvist and breaking with traditional academic modes of representation. Several regions of 

alteration in the yellow paints have been identified in Le Bonheur de vivre, most notably the yellow foliage in the upper left 

corner of the work, the yellow foreground beneath the central 

reclining figures, and the yellow fruits in the tree in the upper 

right quadrant. A 1990 conservation assessment of the work 

first reported that regions of the yellow paint had turned light 

brown and that other areas of the yellow paint had “disintegrated into a fragile powder” (Samet, 1990). The problem is 

most pronounced in the medium impasto brushstrokes of yellow paint under the central reclining figures.

Matisse painted three other works related to this final version (Le Bonheur de vivre, 1905–1906, The Barnes Foundation 

BF719): Sketch for Le Bonheur de vivre (The Barnes Foundation, 

BF35), Esquisse pour “Le Bonheur de vivre” (San Francisco Museum of Modern Art [SFMOMA], 91.160), and Landscape near 

Collioure: Study for The Joy of Life (Statens Museum fur Kunst 

[SMK], Copenhagen). An understanding of the changes that the 

Barnes painting has undergone can be obtained by visually comparing the Barnes work to these related works, especially the oil 

sketch for Le Bonheur de vivre at the San Francisco Museum of 

Modern Art. The San Francisco painting has warm yellow foliage in its upper left corner and a pure bright yellow foreground 

under the central reclining figures. The ocher-hued foliage of the 

upper left corner of the Barnes painting was therefore likely a 

warm yellow color originally, and the mottled ivory hue of the 

paint beneath the central reclining figures would have originally 
number 5 • 5 5

been bright yellow. The dirty white alteration crust of the fruits 

in the tree in the upper right, by this same logic, hides a warm 

yellow color. 

A great deal of elemental, molecular, and microscopic characterization of these altered regions has been carried out by our 

group, and the fading has been attributed to photooxidation 

(Mass et al., 2013a, 2013b). In particular, the off-white alteration crusts are composed predominately of the white cadmium 

compounds cadmium carbonate (CdCO3

) and cadmium sulfate 

(CdSO4

·nH2O; Mass et al., 2013a). Other alteration products 

observed on the painting include lead sulfate (PbSO4

) and cadmium oxalate (CdC2

O4). 

FIGURE 1. Paintings examined for this study. Henri Matisse’s 

(top right) Le Bonheur de vivre, also called The Joy of Life (between October 1905 and March 1906, 691⁄2 × 943⁄4 inches [176.5 × 

240.7 cm], The Barnes Foundation, Philadelphia, BF719), (bottom 

right) Esquisse pour “Le Bonheur de vivre” (The Joy of Life, 40.64 

× 54.61 cm, 1905–1906, SFMOMA, San Francisco, 91.160), and 

(bottom left) Landscape near Collioure: Study for The Joy of Life,

1905, Statens Museum for Kunst, Copenhagen, © 2016 Succession 

H. Matisse/Artists Rights Society (ARS), New York. (top left) Edvard Munch: The Scream 1910(?), Munch Museum, Oslo; Photo © 

Munch Museum.
5 6 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

The SFMOMA and SMK paintings appear to be unaltered 

by photodegradation, with the pigment hues unchanged from 

Matisse’s original intent. This lack of change may result from 

Matisse having used different paints for his work in Collioure 

versus Paris. However, from a preservation perspective, it is critical to know if Matisse did, in fact, use cadmium yellow paints in 

these closely related paintings and, if so, what the current condition of these paints is. 

The cadmium yellow pigments on Edvard Munch’s painting The Scream (ca. 1910?, the Munch Museum) are recently 

reported to have altered to an off-white color (Plahter and 

Topalova-Casadiego, 2011) and have also been studied by a 

number of elemental and molecular analysis methods (Plahter 

and Topalova-Casadiego, 2011). The authors concluded that 

CdCO3

 was not a photooxidation product in this case, but rather 

a synthesis-starting reagent from the indirect wet process synthesis of CdS. Cadmium carbonate is documented to have been 

used as a starting material for both the dry process and indirect 

wet process syntheses of CdS yellow paints (Fiedler and Bayard, 

1986; Plahter and Topalova-Casadiego, 2011). In considering 

the presence of CdCO3

 in The Scream, it is important to note 

that CdCO3

 and cadmium oxalate were also thought to have 

been intentionally added to CdS paints as paint extenders during 

this period (Fiedler and Bayard, 1986). However, this seems like 

an unlikely process in light of the high costs of these materials. 

Edvard Munch’s The Scream overall exhibits alteration phenomena similar to those of Matisse’s Le Bonheur de vivre. A 

cadmium yellow brushstroke in the sky in the upper right has 

faded to an ivory color, as well as two brushstrokes in the central 

figure’s neck. Spalling has also been observed in yellow brushstrokes in the water to the right of the bridge. 

Ultraviolet-Induced Luminescence

of Cadmium Yellow Pigments

The characteristic ultraviolet-induced visible fluorescence of 

CdS (cadmium yellow pigment) was first investigated in the context of artists’ pigments by de la Rie (1982). Fluorescence occurs 

when a compound absorbs electromagnetic radiation at a short 

wavelength, promoting electrons to higher electronic energy 

levels. These electrons then undergo a nonradiative relaxation 

before returning to the ground electronic state, emitting light at 

a longer wavelength (lower energy) than was absorbed as they 

do so. Since fluorescence results from the electronic structure of 

the molecule, it occurs at a fixed wavelength (or wavelengths) regardless of the exact wavelengths of the incident radiation. This 

phenomenon rarely occurs for inorganic artists’ pigments and is 

observed primarily for zinc white and cadmium-based pigments 

(e.g., cadmium yellows, oranges, and reds; de la Rie, 1982). Cadmium pigments fluoresce in the red/orange through the infrared 

as a result of this semiconductor pigment having trace impurities in its crystal lattice. These impurities are generally below 

the minimum detection limits of minor element analysis techniques used at museums such as X-ray fluorescence (XRF) or 

scanning electron microscopy energy-dispersive X-ray spectroscopy (SEM-EDS; de la Rie, 1982). The fluorescence maximum 

for cadmium yellow shifts slightly depending on the pigment’s 

exact composition (cadmium red has a fluorescence maximum 

at a longer wavelength than cadmium orange, which fluoresces 

at a longer wavelength than cadmium yellow); however, the CdS 

maximum occurs at ~750 nm, tailing off into the near infrared at 

~850 nm. By contrast, cadmium orange, CdS1-x

Sex, has a fluorescence maximum at ~800 nm.

It has been suggested that pure CdS will not fluoresce, nor 

will CdS yellow from all manufacturers. However, it must also be 

noted that cadmium yellow paints fluoresce orange not only because of the presence of trace impurities causing deep trap states 

(intermediate energy levels between the semiconductor’s valence 

band and conduction band) but also because of the formation of 

deep trap states that can be a result of surface or internal crystal 

defects in the pigment particles (Thoury et al., 2011). As a result, 

the orange fluorescence can, in theory, be observed in pure cadmium yellow paints. In addition, as noted above there have been 

observations suggesting that although altered cadmium yellow 

paints have a bright orange fluorescence, unaltered cadmium yellow paints can appear brown under ultraviolet illumination (Van 

der Snickt et al., 2009). 

EXPERIMENTAL METHOD

Locating cadmium-based pigments in the paintings was first 

attempted using longwave ultraviolet illumination to excite the 

characteristic visible fluorescence (brilliant reddish orange) for 

the cadmium paints. To block the visible fluorescence interference 

from zinc white and purpurin, this same illumination was used 

again, but this time the fluorescence was collected with a camera 

filter that blocked fluorescence below 715 nm. See Table 1 for a 

summary of the imaging and analysis techniques employed for 

each painting in this study.

Ultraviolet-Induced Visible Fluorescence

At the Munch Museum and at the Statens Museum for 

Kunst a shortwave handheld UV source (a Reskolux UV 365) 

was kept approximately 2 to 4 inches (5.08 to 10.16 cm) away 

from the surface of the paintings to excite the fluorescence of 

the zinc- and cadmium-containing pigments present, as well as 

any fluorescent organic pigments such as purpurin. The visible 

component of this fluorescence, as well as the visible fluorescence 

of all other paintings studied, was collected using a commercial 

handheld digital camera. The Munch Museum also supplied UVinduced visible fluorescence images of The Scream (ca. 1910?). 

These images were collected using a PHILIPS TLD 36w/08, Holland longwave UV source. This is a low-pressure mercury vapor 

discharge lamp that has an inner envelope coated with a fluorescent powder. The dark blue glass envelope transmits UV-A radiation but only minimum visible radiation. The Barnes Foundation 
number 5 • 5 7

ultraviolet illumination source used for the Le Bonheur de vivre

images was a Spectroline lamp with a Spectronics BLE-220B 

Wavelength 365nm (longwave) 4W bulb.

Ultraviolet-Induced Infrared Fluorescence

A Panasonic Lumix DMC-LX5 camera modified by removing the IR-blocking filter was used to image The Scream, Le 

Bonheur de vivre, Esquisse pour “Le Bonheur de vivre,” and 

Landscape near Collioure by employing a visible-light-blocking 

filter that transmitted IR above 715 nm. Ultraviolet illumination 

(described above) was then used to excite both visible and infrared fluorescence of the paintings’ pigments. The 715-nm filter 

blocks the visible light fluorescence of competing pigments such 

as zinc oxide white, allowing only the infrared fluorescence of 

pigments such as cadmium yellow to be detected. 

Portable XRF and XRF

A Bruker Tracer III-SD was used to collect portable XRF 

(pXRF) spectra (rhodium anode, 40 keV, 11 μA, no filter, operating under vacuum [10–35 torr]). Spectra were collected (180-s 

acquisition time) and analyzed using Bruker Artax software. 

This spectrometer was employed for the Barnes Foundation and 

Munch Museum paintings. A Bruker Artax XRF with a Rh tube 

and a He flow was used at the SMK’s Centre for Art Technological Studies and Conservation laboratory for elemental analysis 

of the paints in Landscape near Collioure. Analysis times of 200 

s were used along with a tube voltage of 50 kV and a tube current of 600 or 700 μA. 

Multispectral Imaging

Multispectral imaging for visualization of cadmium red, yellow, and orange pigments in Le Bonheur de vivre was performed 

using blue-green excitation (380–520 nm) obtained with two filtered slide projectors set up at ~45° from the normal at 12 feet 

(3.66 m) from the painting. Multispectral images were collected 

with a silicon CCD camera with 50-nm-spaced filters (40 nm full 

width half maximum). False-color emission maps were generated 

for the emissions at 650, 700, and 850 nm in order to maximize 

the signals generated from CdS and CdS(1-x)

Sex pigments. 

RESULTS

Cadmium Yellow Localization Using Ultraviolet-Induced

Visible Fluorescence Imaging, Ultraviolet-Induced

Infrared Fluorescence Imaging, Multispectral

Imaging, and X-ray Fluorescence

Locating the cadmium-based pigments in Le Bonheur de 

vivre, the two oil sketches related to this work, and The Scream 

(ca. 1910?) was the first step in ultimately imaging the cadmium 

yellow degradation in these works. Ultraviolet-induced infrared 

fluorescence imaging allowed us to view the paintings’ fluorescence in a region where impure cadmium yellow paints and cadmium sulfoselenides are known to have a characteristic emission 

(de la Rie, 1982; Thoury et al., 2011). As mentioned above, this 

method has the advantage of blocking out the fluorescence from 

surrounding pigments and fillers such as zinc oxide white that can 

interfere with imaging the orange fluorescence of the cadmium 

yellow. The results of these measurements were then compared 

to pXRF measurements that were used to map the presence of 

cadmium-based pigments in the paintings. In the case of Le Bonheur de vivre (1905–1906, The Barnes Foundation) multispectral 

imaging was also carried out to assess the efficacy and comprehensive nature of the imaging and analysis methods listed above. 

Ultraviolet-induced visible fluorescence of Le Bonheur de 

vivre (1905–1906, The Barnes Foundation) did not provide comprehensive imaging of the cadmium yellow pigments (Figure 2). 

For example, when this technique is used on the region beneath 

the central reclining figures (which is painted entirely with cadmium yellow according to pXRF analysis), it only reveals the 

TABLE 1. Analysis techniques employed for the paintings studied.

Technique

The Barnes 

Foundation, 

Le Bonheur 

de Vivre

(1905–1906)

Statens Museum 

for Kunst,

Landscape near 

Collioure. Study for 

‘The Joy of Life’

(1905)

SFMOMA, 

Esquisse pour 

“Le Bonheur 

de vivre”

(1905–1906)

Munch Museum,

The Scream

(ca. 1910?)

UV-induced visible fluorescence X X X X

UV-induced IR fluorescence X X X X

Portable X-ray fluorescence X X X X

Multispectral imaging X
5 8 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

locations where the cadmium carbonate–rich alteration crust has 

flaked away to reveal the intact CdS yellow paint underneath. So 

it is observed that only the (relatively) unaltered cadmium yellow 

paint is imaged by this method. Ultraviolet-induced infrared fluorescence (Figure 2b) produced similar results, imaging the visibly intact cadmium yellow paint but not revealing the location 

of the altered cadmium yellow. The altered, photooxidized cadmium yellow paints in Le Bonheur de vivre thus do not all have 

the characteristic orange fluorescence expected for cadmium yellow, likely because of major changes in the electronic structure 

of the pigment as it alters and photooxidizes and the possible 

quenching of the fluorescence by photooxidation by-products. 

The ivory background surrounding the thickly painted blades of 

grass in the image below is altered cadmium yellow, but it has 

minimal orange fluorescence (see Figure 2c) and no fluorescence 

in the infrared. This result is consistent with the thick cadmium 

carbonate and sulfate alteration crusts known to be present in 

this region (according to cross-section photomicroscopy), fully 

removing the CdS semiconductor structure that is required for 

the characteristic fluorescence. 

Even with this limitation, ultraviolet-induced visible fluorescence proved more efficient in this large-scale work for identifying cadmium-based pigments than pXRF analysis. See, for 

example, the yellow centers of the daisies between the pink figures at the lower right of the painting (Figure 1). These flowers, 

which were found to have a bright orange fluorescence when 

studied by ultraviolet-induced visible luminescence, had been 

overlooked as possibly containing cadmium yellow during the 

first round of pXRF analysis. As a result, pXRF and ultravioletinduced visible fluorescence proved to be valuable and complementary, but neither of them was comprehensive on its own. 

The off-white region behind the green embracing figures was 

identified as cadmium yellow using pXRF, but only a small area 

of this discolored region fluoresces, suggesting that the alteration 

crust in this small area is thin enough to allow the fluorescence 

from the intact cadmium yellow to be revealed (see Figure 3). 

Intact cadmium yellow may not be extant in the regions that 

do not fluoresce, or it may be too deeply buried beneath alteration crusts. In either case, this phenomenon highlights a need for 

further molecular analysis in this region of the painting. Note 

that in this area of the painting there are regions of altered CdS 

that have a brownish fluorescence color, thought to be indicative 

of intact cadmium yellow paints. This reveals that a dark appearance of cadmium yellow paint (visible fluorescence) in the 

ultraviolet does not always indicate a lack of photodegradation. 

Multispectral imaging results of Le Bonheur de vivre demonstrate that this is the most comprehensive method for imaging 

cadmium pigments in easel paintings. The results of this technique (Figure 4), using blue-green excitation (380–520 nm), reveal Matisse’s extensive use of cadmium-based yellow, orange, 

and possibly red pigments in Le Bonheur de vivre. These falsecolor emission maps suggest again that the electronic structure 

FIGURE 2. Detail from Le Bonheur de vivre (Barnes Foundation 719, © 2016 Succession H. Matisse/Artists Rights Society (ARS), New York): 

(a) visible light image, (b) ultraviolet-induced infrared fluorescence, and (c) ultraviolet-induced visible fluorescence of the region under central 

reclining figures.

(a) 

(b) (c) 
number 5 • 5 9

FIGURE 4. (a) Visible light image and (b) false-color emission map of Le Bonheur de vivre (Barnes Foundation 719, © 2016 Succession 

H. Matisse/Artists Rights Society (ARS), New York), excited at 380–520 nm (blue-green excitation) and emission/fluorescence recorded for 

650, 700, and 850 nm.

FIGURE 3. Altered cadmium yellow region behind embracing green figures viewed in (a) visible illumination and (b) longwave ultraviolet illumination, Le Bonheur de vivre (The Barnes Foundation, 1905–1906, © 2016 Succession H. Matisse/

Artists Rights Society (ARS), New York).

(a) (b) 

(a) (b) 
6 0 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

of the CdS changes with its state of preservation. Furthermore, 

the fluorescence of other cadmium-containing compounds such 

as cadmium sulfate cannot be excluded. Images (Figure 4) starkly 

reveal the variable nature of the fluorescence of altered cadmium 

yellow paint. Consider, for example, the lightened cadmium yellow to the left of the embracing green figures. In visible light the 

cadmium yellow has faded to a single dirty and mottled ivory 

hue, but the fluorescence phenomena of the species in this region 

vary dramatically. This inhomogeneity of fluorescence reflects 

variability in the alteration products formed on the painting’s 

surface and of the electronic structure of the remaining CdS. 

Alteration products identified thus far on Le Bonheur de vivre

include cadmium sulfate, cadmium carbonate, and cadmium oxalate (Mass et al., 2013a, 2013b). Another cadmium-containing 

species identified in the cadmium yellow paint in Le Bonheur de 

vivre, cadmium chloride, is thought to be present as a residual 

starting reagent (Mass et al., 2013a). Note that multispectral imaging, although comprehensive, is not selective. We cannot now 

use the false-color images to discern which cadmium paints are 

intact versus the altered paints; instead, the image reveals all of 

the cadmium-containing paints present. 

The relatively intact cadmium yellow paint above the embracing green figures demonstrates more fluorescence overall 

than the faded region behind these figures and a more uniform 

fluorescence broken up mostly by patterns of brushstrokes. This 

result appears to confirm the hypothesis that intact CdS is required at the paint layer’s surface for the characteristic fluorescence to be observed. Also note in Figure 4 that the characteristic 

fluorescence of the cadmium yellow paint is visible through 

overlying paint layers when blue-green excitation is used. This 

phenomenon is observed in the outline of the central reclining 

figure, which, although it appears to be three shades of green 

in the visible light image, is revealed to have a cadmium yellow 

brushstroke above the woman’s calf that is now covered by green 

paint. The region beneath and to the left of the central reclining 

figures has faded to a dirty ivory hue. Unlike the region behind 

the embracing green figures, however, this area strongly fluoresces. Importantly, the observation of substantial fluorescence 

throughout this region, not observed for ultraviolet excitation, 

suggests that the use of a longer (blue-green) excitation wavelength penetrates deeper into the painting and excites fluorescence from the buried intact cadmium yellow. 

In sum, although both pXRF and multispectral imaging are 

totally nondestructive, the efficiency and comprehensive nature 

of the latter are demonstrated here. 

Unaided visible light examination for the Statens Museum for 

Kunst’s Landscape Near Collioure (1905) has revealed none of the 

visible evidence of photoalteration observable in the Philadelphia 

painting (see Figure 1). Like the other colors in Matisse’s palette 

for this work, the yellow paints are vibrant and glossy, with no 

evidence of fading, discoloration, chalking, or other alteration 

phenomena. This difference may be due to Matisse having used 

a cadmium yellow deep mixed with a zinc white base in order 

to achieve a cadmium yellow light (this mixture is visible upon 

close examination of the Copenhagen painting), rather than using 

a cadmium yellow light that is formulated with cadmium-based 

filler (or residual starting reagent) such as cadmium carbonate or 

oxalate, as cadmium yellow lights are known to be less stable. 

This change in practice may simply be a result of Matisse having different paint suppliers in the south of France versus Paris. 

Although cadmium yellow was not used in exactly the same locations as it was used in the Barnes Foundation work, XRF was used 

to confirm that it was employed in the foliage in the upper left, 

in the fruits in the trees at the upper right, and in the foreground 

where the central reclining figures appear in the Barnes work. 

As might be predicted from the visual examination of the 

piece, longwave ultraviolet examination revealed no evidence of 

the orange fluorescence associated with altered cadmium yellow 

(data not shown). It is notable that although cadmium sulfide 

particles with surface defects can fluoresce even in the absence 

of photoalteration, this phenomenon is not observed here, suggesting that something about the manufacturing process used to 

produce this pigment batch creates impurities that quench this 

fluorescence or that this “native” fluorescence is too weak to be 

observed under the illumination conditions employed. Similarly, 

no ultraviolet-induced infrared fluorescence is observed for the 

cadmium yellow pigments in this painting. Since both visible and 

infrared fluorescence of cadmium yellow paints can serve as indicators of photoalteration, even before the phenomenon is visible 

to the naked eye, it can be concluded that the cadmium-based 

paints of the SMK work are in excellent condition and that no 

incipient photoalteration is occurring. 

The 1905 oil study for Le Bonheur de vivre at SFMOMA was 

also examined using pXRF, ultraviolet-induced visible fluorescence, 

and ultraviolet-induced infrared fluorescence. As with the Copenhagen work, an overall visual examination of the surface suggests 

that the painting is in excellent condition in terms of the brightness 

of the cadmium yellow colors and their surface condition. 

However, a more detailed examination of the work reveals 

individual brushstrokes that may be starting to show physical 

and chemical alteration due to photooxidative degradation. For 

example, the detail above (see Figure 5a, from the central foreground, below the reclining figures) shows a brushstroke that is 

starting to develop a brownish crust and also appears to have 

faded to an off-white color. However, the brown material may 

be surface soil or residue from a varnish removal, and upon close 

inspection the region was painted with yellow and white paints 

mixed together to create a pale yellow, so a determination of 

fading is challenging to make. Figure 5c (yellow region above 

the embracing green figures) also shows a single brushstroke that 

appears to be developing an ivory alteration crust. However, this 

subtle discoloration is subject to interpretation, and overall, the 

work appears in excellent condition. 

Under longwave ultraviolet illumination, however, both 

of the brushstrokes in question have the characteristic orange 

fluorescence associated with photooxidized cadmium yellow pigments. This finding reveals that ultraviolet-induced visible fluorescence has the potential to be a rapid, inexpensive, portable, 
number 5 • 6 1

FIGURE 5. Visible light and longwave ultraviolet-induced visible fluorescence images from regions of SFMOMA’s Esquisse pour “Le Bonheur 

de vivre,” 1905–1906, 91.160, © 2016 Succession H. Matisse/Artists Rights Society (ARS), New York. (a) Visible light detail of yellow paint 

in central foreground, below the reclining figures. (b) Detail of yellow paint in central foreground under longwave UV illumination showing 

the same brushstroke fluoresces orange. (c) Detail of yellow foliage from the painting’s upper left corner (above the embracing green figures) 

showing a single brushstroke that appears to have a white alteration crust developing. (d) Detail of yellow foliage from the painting’s upper left 

corner, under longwave UV illumination, showing the same brushstroke from (c) fluoresces orange in the ultraviolet.

(c) (d) 

(a) (b) 
6 2 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

FIGURE 6. (a) Ultraviolet-illuminated infrared fluorescence image of The Scream (1910(?), Munch Museum, 

Oslo; Photo © Munch Museum). (b) Visible light image, 

(c) ultraviolet-illuminated infrared fluorescence image, and 

(d) visible light fluorescence image showing cadmium yellow paint brushstrokes in the sky. (e) Visible light image, 

(f) ultraviolet-illuminated infrared fluorescence image, and 

(g) visible light fluorescence image showing cadmium yellow paint brushstrokes in the central figure’s neck and hand.

(a) 

(b) 

(e) 

(c) 

(f) 

(d) 

(g) 
number 5 • 6 3

and accessible imaging technique that can be used to screen for 

the photoalteration of cadmium pigments in its earliest stages, 

when it is difficult or impossible to perceive using the unaided 

eye. Note that all of the paint surrounding the altered brushstrokes shown above is also cadmium yellow and that it does 

not have this characteristic fluorescence, which is unlikely to be 

due to Matisse changing paint sources over such a small area on 

a single work. Instead, this difference among brushstrokes suggests that the orange fluorescence does indeed reveal incipient 

photooxidation. These findings were confirmed by ultravioletinduced infrared fluorescence, which was strongest in these two 

brushstrokes with the dirty appearance (data not shown). 

The ultraviolet-induced visible fluorescence image for The 

Scream (ca. 1910?, Munch Museum) shows the orange fluorescence characteristic of defect-containing cadmium yellow pigments in three prominent brushstrokes in the sky, in the water to 

the right of the central figure, in the railing, and in the clothing of 

the central figure (see Figure 6a). However, only a weak orange 

fluorescence was observed in the swirling water to the right of 

the pair of figures on the bridge, and only one potential brushstroke of characteristic fluorescence for cadmium was observed 

in the central figure’s face or neck. Crucially, pXRF studies of 

the central figure’s face and neck indicate the use of cadmiumcontaining pigments, so ultraviolet-induced visible fluorescence 

is once again not a comprehensive method for identifying cadmium pigments.

The cadmium-yellow-containing paint suspected in the sky 

on the basis of the ultraviolet-induced visible fluorescence was 

clearly imaged using the ultraviolet-induced infrared fluorescence technique (Figure 6c). However, some cadmium-yellowcontaining paints that could not be observed in the sky with 

visible fluorescence could be observed with infrared fluorescence 

(Figure 6b–d). Conversely, note that the bottommost brushstroke 

in the sky that fluoresces orange (Figure 6b,c) and so is clearly 

observable in the visible fluorescence image cannot be definitively 

identified as cadmium yellow using the infrared fluorescence 

image (Figure 6b,d). Portable XRF of this brushstroke confirmed 

the presence of cadmium yellow and vermilion, the yellow and 

red pigments mixed to prepare the orange hue observed. The 

brown fluorescence of much of the cadmium yellow paints in this 

work does not appear to correlate with the condition of these 

paints. Also, unlike the cadmium yellow paint with the brown 

fluorescence observed by Van der Snickt et al. (2009), this paint 

has not been protected from the light, so this fluorescence may be 

due to a lack of photodegradation that more likely results from 

the paint’s formulation than for environmental reasons. 

Competition from other pigments that fluoresce in the visible, 

such as zinc white, prevents the ultraviolet-induced visible fluorescence method from being comprehensive, as does the orange 

fluorescence of cadmium yellow paints being impacted by their 

states of preservation (discussed above for the Matisse paintings). 

As seen in the Matisse works, many of the altered and photooxidized cadmium yellow paints in The Scream (ca. 1910?) do 

have the characteristic orange fluorescence, but not all of them 

(for example, the two yellow brushstrokes altered to an ivory 

color in the central figure’s neck; see Figure 6d–f; cadmium content confirmed by pXRF). This finding may suggest a thick cadmium carbonate and/or sulfate alteration crust (or, in the case 

of such thin brushstrokes, a complete conversion to a mixture 

of alteration phases throughout the paint layer), fully removing 

the CdS semiconductor structure that may be required for the 

characteristic fluorescence. 

This comparison demonstrates that visible fluorescence 

images alone are insufficient to completely map the cadmium 

pigments on a work experiencing cadmium yellow photodegradation and alteration. 

The origin of the orange and near-IR fluorescence of cadmium sulfide pigments has been ascribed to emission from deep 

trap states in the compound’s crystal structure (“native fluorescence”) and also to impurities in the crystal lattice that occur 

during the photodegradation of the compound. In theory, crystal 

defects at the surface of the compound could represent a second 

source of native fluorescence, but this phenomenon was not observed here—unaltered cadmium yellow paint did not fluoresce. 

Much systematic study remains to be done to determine if the 

fluorescence of cadmium sulfide yellow pigments is a reliable 

indicator of their state of photodegradation, which this work 

suggests, particularly for the SFMOMA painting Esquisse pour 

“Le Bonheur de vivre.” However, the different synthesis procedures used by different paint manufacturers must be taken into 

account in these studies since that has been shown to greatly affect the purity of the resulting cadmium sulfide pigments formed, 

particularly at the turn of the twentieth century when the photodegradation of these pigments is found to be prevalent. 

CONCLUSIONS

The photodegradation of cadmium yellow paints can cause 

substantial and irreversible changes in early modernist paintings, 

and it is critical that art conservators and cultural heritage scientists have the tools to identify these changes at their inception. 

It is also critical that they be able to monitor any changes in affected paintings. The four stand-alone imaging and analysis techniques used here were found to be complementary, and each was 

important (in fact, irreplaceable) for identifying cadmium-based 

paints and surveying and understanding their states of preservation. Only pXRF can provide the conclusive identification of 

cadmium paints on the basis of their X-ray emission lines, free 

from interference of pigments that also fluoresce when excited in 

the ultraviolet such as purpurin. Ultraviolet-induced visible fluorescence was found not to comprehensively identify cadmium 

paints on altered works such as The Scream (ca. 1910?) or Le 

Bonheur de vivre (1905–1906). Instead, cadmium yellow paints 

that were severely altered did not have the characteristic orange fluorescence expected for CdS, likely because of alteration 

crusts rich in other compounds such as CdCO3

 and CdSO4 that 

have different electronic structures. Ultraviolet-induced visible 
6 4 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

fluorescence was useful for imaging the cadmium pigments at 

the beginnings of alteration process, when impurities forming 

in the crystal lattice cause the deep trap states responsible for 

the semiconductor pigment’s characteristic fluorescence. As a 

result, this imaging technique will prove critical for identifying 

paintings right at the start of a pressing preventive conservation need. 

Ultraviolet-induced infrared fluorescence was found to 

be a useful confirmatory technique for the visible fluorescence 

technique and also critical for identifying altered cadmium yellow brushstrokes in the neck of the central figure in The Scream

(Munch Museum, ca. 1910?). Further work is needed to determine why certain altered cadmium paints exhibit fluorescence in 

the infrared and not the visible. Finally, multispectral imaging 

has great promise for comprehensively imaging cadmium pigments using their near-infrared luminescence. The excitation 

wavelengths used here (380–520 nm) excited fluorescence in all 

of the cadmium pigments, altered and unaltered, in Le Bonheur 

de vivre (1905–1906). 

Acknowledgments

We gratefully acknowledge the National Science Foundation for funding W&L’s portable cultural heritage instrumentation (NSF MRI grants CHE-0959625 and CHE-1337481).

REFERENCES

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Jatte—1884. Analytical and Bioanalytical Chemistry, 399(9):2909–2920. 

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J. Groenewegen, and L. Van der Loeff. 2009. Characterization of a Degraded 

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ABSTRACT. This paper examines Kazimir Malevich’s (1878–1935) materials and methods for 

his Painterly Realism of a Football Player—Color Masses in the 4th Dimension painted in 1915. 

Football Player is an impressive painting constructed of colored geometric forms, representative of 

Kazimir Malevich’s Suprematist period. This painting is from a remarkable group of works the artist 

produced for 0.10 (Zero–Ten): The Last Futurist Exhibition of Painting held in Petrograd in 1915 

where Malevich’s Suprematist works debuted. The pristine condition of Football Player allows for 

the accurate interpretation of Malevich’s artistic vision and makes this painting an excellent candidate for a technical study using noninvasive techniques. Methods used included X-ray, infrared 

reflectography, and ultraviolet visible fluorescence imaging, microscopic examination, and analysis 

of pigments and binding media using X-ray fluorescence spectroscopy (XRF) and reflectance Fourier 

transform infrared spectroscopy (FTIR). Results from XRF analysis showed a closely similar palette 

to other Suprematist paintings by Malevich and highlighted the presence of paints in limited use 

such as cobalt violet, whereas reflectance FTIR results provided new insights into the binding media 

used, the condition of the oil paint, and the presence of extenders, organic additives, and degradation products.

INTRODUCTION

Kazimir Malevich (1878–1935) is one of the most significant and rigorous pioneers 

of abstraction. He led the way to total nonobjective abstraction with his own variant, 

which he named Suprematism, in 1915. For a few years before this, he had been working 

in a Cubo-Futurist style, translating images of figures and everyday objects into complex 

compositions influenced by the speed of modern life. His particular experiments in 1914 

with zaum (literally, beyond the mind) or “transrational” painting—a term adopted from 

the Russian poets Velimir Khlebnikov (1885–1922) and Aleksei Kruchenykh (1886–

1968) to mean language beyond logic or acquired meaning—further challenged the conventions of representational art.1

Over the summer and fall of 1915 Malevich worked in absolute secrecy in his studio making works of art that would demonstrate his new and revolutionary approach. 

His goal was to contribute a significant number of paintings for the exhibition 0.10 

(Zero–Ten): The Last Futurist Exhibition of Painting, organized in Petrograd by the artist Ivan Puni (1892–1956) and his wife, Ksenia Boguslavskaia (1892–1972), which aimed 

to present the 10 artists included as those seeking to find the most elemental, irreducible 

base (the “zero”) of painting.2

 As Malevich wrote in June of that momentous year, 

The Art Institute of Chicago, 111 S. Michigan 

Ave., Chicago, Illinois 60603, USA.

* Correspondence: M. Kokkori, mkokkori@

artic.edu

Manuscript received 7 July 2014; accepted 22 

February 2016.

Materials and Meanings: Analyzing Kazimir 

Malevich’s Painterly Realism of a Football 

Player—Color Masses in the 4th Dimension

Maria Kokkori,* Stephanie D’Alessandro, Kristin Lister, 

and Francesca Casadio
6 6 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

All previous and contemporary painting before 

Suprematism—sculpture, the word, music—were enslaved by the form of nature, and they await their 

liberation in order to speak in their own tongue and 

not depend upon intellect, sense, logic, philosophy, 

psychology, the various laws of causality and technical 

changes in life. . . . The striving of the artistic powers 

to direct art along the path of intellect produced a zero 

of creativity . . . but I have transformed myself into a 

zero of form and gone beyond “0” to “1” . . . I cross 

over to Suprematism, to the new realism in painting, to 

objectless creation.3

In preparation for this exhibition, Malevich produced a series of over 40 paintings that completely eradicated all references 

to the recognizable world and focused instead on the inherent 

relationships of strictly geometric shapes of various colors that 

float on top of white backgrounds. The powerful icon-like presence of these works was emphasized by their presentation in the 

exhibition: arranged in three rows across the walls of a room 

dedicated to the artist and crowned by Malevich’s Black Square

(1915; State Tretyakov Gallery, Moscow), which hung high 

above in a corner. The works in this exhibition set the course 

for much of the development of abstract art thereafter and are 

recognized today as objects of great aesthetic as well as historic 

merit. One of those is the work discussed here, Painterly Realism 

of a Football Player—Color Masses in the 4th Dimension, a remarkably bold and dynamic canvas that significantly augmented 

the Art Institute of Chicago’s holdings of modern art upon its 

acquisition in 2011 (Figure 1).

PROVENANCE

Painterly Realism of a Football Player—Color Masses in 

the 4th Dimension was in Malevich’s possession when he was 

invited in 1927 to present a retrospective of his work in Warsaw, Poland, and at the Grosse Berliner Kunstausstellung (Great 

Art Exhibition) in Berlin, Germany. Within the larger presentation of at least 70 paintings, Malevich also showed about 22 

research tables that introduced his investigations of modern art, 

the “science of painting” (zhivopisnaia nauka) as he described 

it, carried out at the State Institute for Artistic Culture in Petrograd (GINKhUK) between 1923 and 1926, and 27 Suprematist 

works, including Football Player.

4

 Malevich was obliged to return to the Soviet Union before the exhibition’s end and left his 

works in the care of architect Hugo Häring (1882–1958). At 

Malevich’s request, none of the works were to be returned to him 

in Moscow since he had hoped to return to Europe the following 

year to exhibit his work in Paris and other west European cities and possibly even remain in the West.5

 Following Malevich’s 

death in 1935, the collection remained with Häring until 1957, 

when he was convinced through the advice of artist Naum Gabo 

(1890–1977) and architect Mies van der Rohe (1886–1969) to 

transfer all the remaining 84 works to the Stedelijk Museum 

in Amsterdam. Football Player stayed in the collection of the 

Stedelijk until 2008, when it was returned, along with four 

others, as part of a settlement with Malevich’s heirs.6

HISTORICAL CONTEXT

The painting is executed in oil paint on a canvas support 

and titled by Malevich “Football Player” as inscribed on the 

verso and dated 1915 (Figure 1). The first part of the title, Painterly Realism of a Football Player, may have been a reference to 

Albert Gleizes (1881–1953) and Jean Metzinger’s (1883–1956) 

FIGURE 1. Kazimir Malevich, 1915. Painterly Realism of a Football Player—Color Masses in the 4th Dimension, oil on canvas, 

27 × 17 1/2 in. (71 × 44.5 cm). ©The Art Institute of Chicago.
number 5 • 6 7

discussion on “realism” in their treatise Du “Cubisme” published in 19127

 and Umberto Boccioni’s (1882–1916) futurist 

painting Dynamism of a Soccer Player (oil on canvas, 193.2 × 

201 cm, The Museum of Modern Art, New York), painted in 

1913, which was well known among Russian avant-garde artists 

as it was reproduced in contemporary art journals. The second 

part of the painting’s title, Color Masses in the 4th Dimension, 

refers to the mathematical theory of fourth-dimensional space, 

a concept appropriated by many early twentieth-century avantgarde artists to justify their work beyond immediate sensory perception. For Malevich, Suprematism was intimately linked with 

a transforming and modern, mystical experience associated with 

concepts of space-time physics and the notion of the fourth dimension. These ideas had been introduced in the 1880s by the 

British mathematician Howard Hinton (1853–1907) and Russian philosopher Peter Uspenskii (1878–1947) and centered on 

the concept of a space outside sensory perception that made the 

present world illusory.8

 The title of the painting reflects this concept: although it references the natural world, it also breaks with 

it, moving far beyond description to depict its subject in lines and 

planes freed from the weight of the third dimension. As Malevich explained, “in naming some of the paintings I do not wish 

to point out what form to seek in them, but I wish to indicate 

that real forms were approached in many cases as the ground 

for formless painterly masses from which a painterly picture was 

created, quite unrelated to nature.”9

 Indeed, recent scholarship 

has proven just how distanced from depiction Malevich had become, as evidenced by the deep geometric interconnectedness of 

all the works he produced for 0.10, which can even be traced 

to their exact placement and interaction on the walls. Furthermore, Malevich would soon give up the last vestige of the art 

of representation—the notion of a proper “top” and “bottom” 

for his canvases—in favor of a “new logic of a non-referential 

space.”10 Malevich’s paintings achieved the look of modern-day 

icons, and he specifically envisioned their place in a new, modern world. He believed Suprematism to be “the beginning of a 

new culture . . . a new form [that would] announce that man has 

gained his equilibrium.”11 Paintings like Painterly Realism of a 

Football Player were metaphysical and spiritual tools meant to 

raise human consciousness. This utopian view had even greater 

urgency with the October revolution of 1917, and his Suprematist paintings’ appearance—simple, pure, modern—became, 

for a time, part of the visual idiom of the new society. But for 

all their look of being preordained absolute signs, under close 

examination the works reveal the extreme care, complexity of 

execution, and thinking of the artist. 

TECHNICAL EXAMINATION 

AND SCIENTIFIC ANALYSIS

Kazimir Malevich was an avid writer, aspiring constantly to 

express and explain his artistic beliefs and methods, especially as 

they related to his Suprematist system. In spite of the very large 

art historical literature devoted to the painter, there is surprisingly little on his methods and materials.12 This dearth of technical literature is perhaps due to the mistaken assumption that the 

works of art may be technically simplistic, especially in regard to 

his Suprematist paintings.

The combination of exacting abstract forms rendered in pure 

colors and the remarkable condition of this painting made it the 

perfect candidate for a noninvasive investigation of his materials and techniques. For this examination a combination of complementary noninvasive techniques was used, including X-ray, 

infrared reflectography, ultraviolet imaging, and microscope 

examination. The analysis of pigments and binding media was 

achieved with X-ray fluorescence spectroscopy (XRF) and reflectance Fourier transform infrared spectroscopy (FTIR; Table 1).

TABLE 1. Results of the paint analyses using X-ray fluorescence spectroscopy and reflectance Fourier transform infrared spectroscopy.

Paint Pigments Extenders Additional components

White Lead white (ground layer), zinc white 

(paint layers)

Barium sulfate (and/or lithopone), 

manganese and silica compounds

Zinc stearates, zinc oxalates, 

manganese palmitate

Black Ivory black Wax

Yellow Lead chromate Hydrated magnesite

Red Vermilion Hydrated magnesite and silica compounds

Green Emerald green Barium sulfate, magnesium carbonate Dammar

Blue Ultramarine blue Hydrated magnesite Zinc stearate

Violet Cobalt violet, cobalt blue, 

ultramarine blue

Barium sulfate Zinc stearate, dammar
6 8 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

RESULTS AND DISCUSSION

Painting Techniques and Materials

In Malevich’s Suprematist paintings he sought to position 

geometric forms in space and to intuitively suggest their directional movement by implying forces, such as attraction and repulsion, that would lead to their alignment, concentration, or 

dispersal. Malevich maintained order in his painting process and 

control of subtleties in order to achieve this vision. Variations 

in the mass, position, and shape of his forms were critical to 

intended forces and effects and often required adjustments at 

different stages of the painting process. X-ray images revealed 

changes in composition, especially in the black geometric shapes 

in the lower part of the painting (Figure 2). Evidence from infrared reflectography (IRR) also showed many reworked lines, 

reconsidered placements, and revised sizes of forms, as the artist 

altered the composition. (Figure 3). In this work, the forms occupy two separate ends of the picture plane. The paint quality 

and brushwork of the two halves also vary slightly, corresponding to the difference in forms depicted. Malevich painted with 

two sets of complementary colors—the purple/yellow contrast 

of larger forms over a wider range at one end and the red/green 

contrast of smaller forms over a shorter span at the other end. 

This palette of contrasting colors is augmented by the curve of 

the dark rectangles, from purple to black to red in a tonal continuum across the picture plane. Thus, the entire canvas represents a 

rectangular form—a playing field whose borders concentrate the 

energy and exert a force on the purple parallelogram—effectively 

transforming it into a more dynamic shape. 

For Football Player, Malevich used a medium-sized fineweight plain-weave linen canvas stretched over a nonstandard 

size wooden stretcher and began his composition on a lead 

white–chalk ground that he applied thinly so that the texture of 

the canvas remained prominent, sketching in charcoal the forms 

he would later paint following his preliminary outlines. The paint 

layers followed around the sketched forms along with a second 

slightly different layer of white. Under ultraviolet illumination, 

FIGURE 2. X-ray image showing changes in composition, especially in the black geometric forms in the lower part of the painting. Left: overall. 

Right: detail of lower half. ©The Art Institute of Chicago, Conservation department.
number 5 • 6 9

the top white layer exhibits the bright yellowish white autofluorescence, characteristic of zinc oxide (Figure 4).

The XRF analysis confirmed the presence of lead white 

(basic lead carbonate) found to be present throughout and to 

originate from the ground layer,13 whereas zinc white (zinc 

oxide) has been identified as used for the white background and 

in admixtures with the paints.

Forms were delineated using a card as a guide to create a 

straight-edged colored border. Forms were then painted with 

green, black, red, blue, yellow, or purple. Malevich may have 

applied some of the colors while the white paint layer was still 

partially wet, as evidenced by impressions left by the card edge. 

Once the forms were established on the canvas, Malevich painted 

the space surrounding the forms in zinc white paint: at the bottom of the composition he worked the paint straight out of the 

tube for more control in short energetic strokes; on the top, he 

painted with fluid brushstrokes across the open field of the canvas. The traces of his working methods—the raised impressions 

in the still-wet paint the cards made as they were removed from 

the painting’s surface, the flattened high spots on the white paint, 

the imprint of the cards’ outer edges revealing their sizes, even 

Malevich’s own fingerprints in the white paint above the black 

square—can be seen across the paint surface, suggesting a far 

FIGURE 3. Details of the IRR image showing reworked lines and revised sizes of geometric forms visible in the lower half of the painting. Left: 

bottom half of the painting. Right: detail from the lower right quadrant. ©The Art Institute of Chicago, Conservation department.

FIGURE 4. Ultraviolet image showing a bright yellowish white autofluorescence, characteristic of zinc oxide. ©The Art Institute of Chicago, 

Conservation department.
7 0 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

more organic and intuitive process than might be inferred from 

the spare abstract composition (Figure 5).

Ground Layer and White Paint Composition

To characterize the ground, six spots spanning various areas 

of the white painted ground in the painting were analyzed with 

reflectance FTIR spectroscopy. All spectra were fairly similar, 

with minor variations in the drying oil binder. The presence of 

zinc oxide was also confirmed (Figure 6).14

The XRF analysis also detected the presence of varying 

amounts of barium in white passages, likely indicating the use of 

barium sulfate as an extender in the tube paint formulation used 

by Malevich. A more significant amount of barium was found in 

the ground layer than the upper paint layers. Because the analysis detected both barium and zinc in the white paint, the presence of lithopone cannot be completely excluded.15 These results 

require confirmation by a complementary technique such as UV/

visible fiber-optic reflectance spectroscopy (FORS; in the range 

300–800) or Raman in situ, which were unavailable at the time 

of this study.

Yellow Paint

The trapezoidal yellow form crossed by a blue bar was 

painted in two sections. All yellow areas examined with reflectance FTIR showed lead chromate (with bands centered at 860–

880 cm−1) confirmed by XRF detection of chromium and lead. 

FIGURE 5. Details of Football Player showing the paint application. (a) Lower half of yellow form showing evidence of use of a 

card as a guide to create straight lines; the different textures of the two white paints are also evident. (b) Detail of the trapezoidal 

yellow form crossed by a blue bar showing small areas of exposed white underlayer. (c) Detail of the green circle showing the artist’s 

underdrawing. (d) Detail of the purple trapezoid showing the paint texture. ©The Art Institute of Chicago, Conservation department.
number 5 • 7 1

The presence of paint extender based on hydrated magnesite was 

confirmed with reflectance FTIR.16 Around the form the texture 

of the thin ground over the canvas is visible (Figure 5a), whereas 

the surrounding areas of the background are covered to different degrees with the glossy top layer, which appears smooth or 

shows traces of brushwork when thicker or, when thin, exposes 

the color and texture of the ground. The layer structure of the 

yellow paint varies above and below where it is intersected by 

the blue bar, as evident in the IRR image (Figure 3), as well as 

from XRF analysis, which detected chromium above and below 

but not underneath the blue bar; hence, we can assume there is 

no yellow under the blue. Comparison of the XRF spectra of 

the upper and lower parts of the yellow trapezoid form bisected 

by the blue bar showed that the lower part had greater intensity 

for Zn, suggesting that Malevich first painted the yellow shape 

up to the border area with the blue bar but not extending below 

it; he then added more zinc white paint around it and, finally, 

painted on top of the zinc white layer the lower part of the yellow form. 

Black Paint

It is evident that Malevich made several subtle changes to the 

forms as he drew the composition on the canvas. Although infrared reflectography is not effective for revealing underdrawing 

beneath a black paint layer, it revealed charcoal lines extending 

beyond the edges that indicated a narrower form was originally 

planned for the black rectangle. Malevich also enlarged the black 

square slightly over a centimeter in each direction, bringing the 

forms into a tighter grouping, as evident from the X-radiograph. 

Reflectance FTIR analysis of the black forms identified bone 

black.17 In the XRF analysis, the lower part of the square shows 

higher-intensity peaks for Zn, suggesting reworking in the area 

after the artist had applied the second white background layer 

around the forms. Under high magnification it is evident that 

Malevich also repainted the adjacent ends of the blue bar so that 

they align with the edges of black square. 

Red and Blue Paint

In other changes during the coloring stage, Malevich extended the red rectangle several centimeters farther toward the 

right edge of the painting. The XRF detection of mercury in red 

areas is an indication of the use of vermilion extended with hydrated magnesite and containing trace silicates as confirmed by 

reflectance FTIR. 

Reflectance FTIR analysis of the blue bar confirmed the 

presence of ultramarine blue.18 This is in line with both historical 

and artistic documentation, and scientific analysis of Malevich 

artworks revealed his extensive use of French ultramarine.19

Green Paint

On the green area, XRF analysis identified a strong correlation between copper and arsenic, suggesting the use of a copper 

arsenite pigment, such as emerald green.20 This is consistent with 

Malevich’s practice as it has been reported that emerald green 

was one of the most commonly found pigments on Malevich’s 

oil paintings. Scheele’s green21 cannot be completely excluded; 

Malevich’s use of Scheele’s green is less likely since it was no 

longer in use at the end of the nineteenth century because of its 

tendency to blacken. The FTIR analyses also indicated the presence of chrome yellow, barium sulfate, and dammar varnish. Interestingly, XRF results showed that zinc was absent in the green 

area, whereas it was present in all other colored areas analyzed, 

suggesting that the green ball is painted directly on the ground 

layer, as the first colored geometric form Malevich positioned on 

the canvas. 

Violet Paint

Malevich expanded the violet form on three sides, so that 

instead of painting within an area of reserve, he painted over the 

wet zinc white paint. Because the artist painted the purple over 

the edge of the surrounding white background, although he did 

so very precisely, the two colors do mix slightly in some strokes. 

In the purple parallelogram, Malevich painted with cobalt violet, 

a pigment known for its transparency. He carefully controlled the 

brushwork, applying thin, parallel strokes to extend the paint. He 

also went back with the brush and texturized some of the thicker 

deposits of purple. In the examined purple areas, reflectance FTIR 

also indicated the presence of zinc stearates, barium sulfate, zinc 

white from the white under layers, and dammar resin—possibly 

FIGURE 6. The FTIR reflection spectrum of the white painted area 

(Znox: zinc oxalates; ZnSt: zinc stearates; MnP: manganese palmitate; Pbw: lead white; Sulf or Sil: sulfates and/or silicates).
7 2 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

added by Malevich to increase the sense of depth, transparency, 

and gloss of the painted form (Figure 7).22, 23

Cobalt violet was an expensive color to buy in early 

twentieth-century Russia, and it was specifically mentioned in 

the technical literature, including manuals written by Malevich’s 

teacher, Fedor Rerberg (1865–1938), as being a pigment for use 

in exceptional cases such as exhibitions and similar events. Its 

visual and handling properties and its transparency allowed it to 

be used in painting to create rich enamel-like effects.24 It was extensively discussed by Russian avant-garde artists within the context of faktura, translated in English as “texture,” “facture,” or 

“structure,” and materiality in art and also provided inspiration 

to poets. Cobalt violet pigment had literary, political, and social 

connotations; it became synonymous with European modernism and was often described in Russian literature as a “French” 

or “bourgeois” pigment. In avant-garde poetry, colors were essential, for they conveyed mystical intimations of things beyond 

human experience. In 1904, Aleksandr Blok (1880–1921), for 

example, wrote the famous poem “Such a violet west is oppressive” (fioletovyi zapad gnetet),25 and Vladimir Mayakovsky 

(1893–1930), in his Verlaine and Cézanne (Verlen i Sezan), stated 

that the color of “Paris is violet.”26 After the October revolution 

of 1917 the availability of cobalt violet became scarce since the 

trade with western European countries was cut off.

Condition of the Painting

Considering the fate of avant-garde art in Russia and Germany, the cataclysmic destruction of Berlin in World War II, and 

the general wear and tear that can ravage any artwork that is 

exposed to adverse conditions, it is remarkable that Painterly 

Realism of a Football Player survived in such good state, unlike 

many other paintings from the Russian avant-garde.27

In the present study, a number of carboxylate soaps were 

detected, such as zinc stearates and oxalates, manganese palmitate, and possibly copper oxalates. Although some of these compounds may be deliberate additions by the paint manufacturer as 

paint driers and dispersants, many should be considered deterioration products and may have an impact on future conservation 

choices.

Surface and Facture

In Cubo-Futurist works preceding Football Player Malevich 

made use of differences in texture and gloss and applied local 

varnishes for subtle distinctions in surface appearance. Football Player is consistent with this practice since an aged natural 

resin varnish, locally applied, can be detected on the purple and 

green form and may well be original. Malevich would have deliberately applied varnish to the purple/violet form to enhance 

its transparency. Elsewhere in the composition, the yellow form 

painted with lead chromate is very opaque and in contrast to the 

purple form positioned above. 

As previously indicated, the study of color and faktura were 

fundamental in the development of Suprematism, “the essence 

of painting,” as Malevich wrote.28 Faktura was a basic principle 

of avant-garde art—the specific combination of materials and 

painting techniques used within the creative process that lead 

to the sensation experienced when viewing the work of art, denoted the material quality of a work of art: the way of making it, 

the materials used, the paint layers, and their opacity and transparency. The term used extensively by Cubo-Futurist and Suprematist artists and then by Futurist poets and Formalist theorists 

was quickly adopted by the Constructivists to express a materialist ideology and utilitarian orientation in artistic production.29

Faktura was explored by Malevich and his students as an idea, a 

formless phenomenon, a technological or scientific development, 

and a focus for future discoveries. 

CONCLUSIONS

Malevich’s Football Player is a work of incredible delicacy 

and subtle, dimensional painting; its surface is full of contrasting 

texture, color, opacity, and finish. The powerful and dynamic 

composition, which at first may seem technically simplistic, exhibits a complexity of brushwork and revisions that are the hallmarks of Malevich’s preoccupation with color, form, and texture. 

This study has been made possible by new developments in 

noninvasive analytical methods that yield significant information 

about the artist’s methods and materials and allow detailed and 

critical analysis and imaging of an artwork’s entire structure.30–36

The study of this painting integrating X-ray fluorescence with 

FIGURE 7. The FTIR reflection spectrum of the purple painted area 

(ZnSt: zinc stearates; ZnO: zinc white; U: ultramarine blue; CoV: 

cobalt violet; BaS: barium sulfate; D: dammar).
number 5 • 7 3

infrared spectroscopy confirmed Malevich’s palette included 

lead white, zinc white, vermilion, lead chromate yellow, bone 

black, emerald green, ultramarine blue, and cobalt violet with 

some cobalt blue. Although, overall, the binding medium of the 

paint was confirmed as oil, local application of dammar resin 

varnish was detected on the purple form, an example of Malevich’s expert paint handling and careful attention to faktura in 

his Suprematist oeuvre. 

Acknowledgments

The authors thank Frank Zuccari, Kim Muir, Allison Langley, Kelly Keegan, and the staff of Ryerson & Burnham Libraries 

at the Art Institute of Chicago and John Delaney and Kate Dooley, 

National Gallery of Art, Washington, D.C., for preliminary, confirmatory FORS measurements. The financial support of the Stockman Family Foundation, the Andrew W. Mellon Foundation, and 

the Grainger Foundation is also gratefully acknowledged.

APPENDIX

X-ray Fluorescence Spectroscopy

Analysis was performed using a Bruker TRACeR III energy 

dispersive X-ray fluorescence analyzer, with a Peltier cooled 

Silver-free SiPIN detector with a 13-μm Be window and a resolution of approximately 175 eV for the full width at half maximum 

of the Mn Ka line. The system is equipped with a rhodium transmission target. Analysis was conducted at 45 kV and a beam 

current of 2.0 μA pulling a vacuum at the tip of the instrument 

to enhance light element detection. Acquisition time was 120 s. 

The size of the analyzed spot may vary, but it is approximately 

6–8 mm in diameter.

Reflectance Fourier Transform Infrared Spectroscopy

A portable Bruker-Alpha FTIR spectrometer equipped with 

a deuterated triglycine sulfate (DTGS) detector was used. Spectra 

were collected as the sum of 256 scans at 4 cm−1 resolution. 

NOTES

1. For more on the concept of zaum, see Charlotte Douglas, Swans of Other 

Worlds: Kazimir Malevich and the Origins of Abstraction in Russia (Ann 

Arbor, MI: UMI Research Press, 1980); Gerald Janecek, Zaum: The Transrational Poetry of Russian Futurism (San Diego: San Diego State University 

Press, 1996).

2. Linda S. Boersma, 0.10: The Last Futurist Exhibition of Painting (Rotterdam: 010 Publishers, 1994).

3. Kazimir Malevich, Ot kubizma i futurizma k suprematizmu: novyi zhivopisnyi realizm (Moscow: tip. Obshchestvennaia Pol’za, 1916), 11–27.

4. Troels Andersen, Malevich: Catalogue Raisonné of the Berlin Exhibition 

1927 (Amsterdam: Stedelijk Museum, 1970); Maria Kokkori and Alexander Bouras, “Charting Modernism: Kazimir Malevich’s Research Tables,” in 

Malevich, ed. Achim Borchardt Hume. (London: Tate, 2014), 164–195.

5. J. M. Joostens, “Malevich in the Stedelijk,” in Kazimir Malevich 1878–1935, 

ed. W. A. L. Beeren (Amsterdam: Stedelijk Museum, 1988), 44–54.

6. Leonard Malewicz et al., Plaintiffs, v. City of Amsterdam, Defendant. United 

States District Court, District of Columbia. 517 F. Supp.2d 322. D.D.C. 

2007.

7. Albert Gleizes and Jean Metzinger, “Du ‘Cubism’ [27 December 1912],” in 

A Cubism Reader: Documents and Criticism 1906–1914, ed. M. Antliff and 

P. Leighten (Chicago: University of Chicago Press, 2008), 435. 

8. For more on Malevich’s interest in the fourth dimension, see Linda Dalrymple 

Henderson, The Fourth Dimension and Non-Euclidean Geometry in Modern Art (Princeton, NJ: Princeton University Press, 1983), 274–294; John 

Golding, “Malevich and the Ascent into Ether,” in Paths to the Absolute: 

Mondrian, Malevich, Kandinsky, Pollock, Newman, Rothko, and Still, A. W. 

Mellon Lectures in the Fine Arts, 1997 (Princeton, NJ: Princeton University 

Press, 2000), 47–80.

9. Henderson, The Fourth Dimension, 287, n. 185. 

10. This decision, in combination with photographs of his 1915, 1920, and 1927 

exhibitions, which record the changing orientation of certain paintings, has 

led to differing interpretations about whether Malevich reconsidered the orientation of his Suprematist compositions. Painterly Realism of a Football 

Player was shown twice with the purple form at the top (1915 in Petrograd 

and 1927 in Berlin) and twice with the form at the bottom (1920 in Moscow 

and 1927 in Warsaw). 

11. Malevich, Ot kubizma i futurizma k suprematizmu, 27.

12. Milda Vikturina and Alla Lukanova, “A Study of Technique: Ten Paintings by 

Malevich in The Tretiakov Gallery,” in Kazimir Malevich, 1878–1935 (Los 

Angeles: Armand Hammer Museum of Art and Cultural Center, 1990), 187–

197; Ann Hoenigswald, “Kazimir Malevich’s Paintings: Surface and Intended 

Appearance,” in Conservation Research, 1996/1997, Studies in the History 

of Art 57, Monograph Series II (Washington, D.C.: National Gallery of Art, 

1997), 109–125; Yulian Khalturin, “Kazimir Malevich’s Artistic Method and 

Evolution of His Painting Technique” (Ph.D. diss., Lomonosov Moscow State 

University, 2006); Maria Kokkori, “Russian Avant-Garde Art: A Historical 

Contextualization of Selected Paintings by Kazimir Malevich, Ivan Kliun, and 

Liubov Popova c.1905–1925” (Ph.D. diss., Courtauld Institute of Art, 2008); 

Maria Kokkori and Alexander Bouras, “The Painting Techniques of Kazimir 

Malevich: 1900–1910,” in Painting Techniques, History, Materials and Studio 

Practice (Amsterdam: Rijksmuseum, 2015, in press). 

13. It can be deduced that lead white is confirmed because of the inversion of the 

intensity of the Pb La and Lb lines when the XRF analysis was conducted 

in the recto and also because a stronger signal from Pb was observed when 

acquiring the XRF spectra from the verso of the painting/canvas.

14. The drying oil binder was characterized by the doublet at 4,340–4,250 cm−1

ascribed to the ν + D(CH) mode of aliphatic chains and the first overtone 

of ν(CH) at about 5,800–5,680 cm−1, as well as the ν(CO) band centered 

at 1,740 cm–1. The ν(CH) bands of the oil medium are obscured by strong 

and sharp absorption bands inverted by the reststrahlen effect centered at 

2,916 and 2,848 cm−1, which, in association with the sharp negative peak at 

1,540 cm–1 assigned to ν(COO−

), clearly identify the presence of zinc stearates. 

Other carboxylate soaps were also identified, namely, zinc oxalates indicated 

by the inverted bands at 1,630, 1,364, 1,320, and 824 cm−1 as well as manganese palmitate (1,569, 1,544, 1,451, 1,429, 1,420, and 1,404 cm−1). Zinc 

oxide was confirmed in all examined areas because of the broad reststrahlen

inverted band with inception at 700 cm−1. The sharp inverted peak at 1,272 

cm−1 could possibly be associated with cellulose nitrate or a plasticizer containing phthalate attributed to previous conservation treatments. For more 

on noninvasive analysis using reflected FTIR, see M. Vagnini, C. Miliani, 

L. Cartechini, P. Rocchi, B. G. Brunetti, and A. Sgamellotti, “FT-NIR Spectroscopy for Non-invasive Identification of Natural Polymers and Resins in 

Easel Paintings,” Analytical and Bioanalytical Chemistry 395, no. 7 (2009): 

2107–2118, http://dx.doi.org/10.1007/s00216-009-3145-6; R. Mazzeo, 

S. Prati, M. Quaranta, E. Joseph, E. Kendix, and M. Galeotti, “Attenuated 

Total Reflection Micro FTIR Characterisation of Pigment-Binder Interaction 

in Reconstructed Paint Films,” Analytical and Bioanalytical Chemistry 392, 

nos. 1–2 (2008): 65–76, http://dx.doi.org/10.1007/s00216-008-2126-5; 

B. Doherty, M. Pamplona, R. Selvaggi, C. Miliani, M. Matteini, A. Sgamellotti, and B. Brunetti, “Efficiency and Resistance of the Artificial Oxalate Protection Treatment on Marble against Chemical Weathering,” Applied Surface 

Science 253, no. 10 (2007): 4477–4484, http://dx.doi.org/10.1016/j.apsusc

.2006.09.056.

15. Although occasionally used for artists’ paints, lithopone extenders were extensively used in the house paint industry.
7 4 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

16. The examined areas were characterized by bands at 433, 598, 851, 880, 

1,428, 1,480 3,449, and 3,514 cm–1 and a particularly diagnostic sharp −OH 

stretching band at 3,647 cm−1.

17. A diagnostic sharp positive peak at 2,014 cm−1 is combined with peaks between 1,600 and 1,320 cm-1 and bands ascribed to vibrations of the phosphate group with reststrahlen inverted bands with a minimum at 1,024 cm−1

and positive peaks at 964 and 876 cm−1. The ν(CH) area showed sharp 

negative peaks at 2,915 and 2,843 cm−1 associated with weak peaks at 

717–730 cm−1, likely related to the presence of wax, possibly connected with 

the wax lining treatment of the canvas. For more on spectral distortions in 

reflected FTIR, see C. Miliani, F. Rosi, A. Daveri, and B. G. Brunetti, “Reflection Infrared Spectroscopy for the Non-invasive in Situ Study of Artists’ 

Pigments,” Applied Physics A 106, no. 2 (2012): 295–307, http://dx.doi.org

/10.1007/s00339-011-6708-2.

18. The reflectance FTIR spectra showed characteristic bands for ultramarine 

blue with negative peaks centered at 577 and 640 cm−1 and a reststrahlen

inverted peak for the ν(Si-O) with a minimum around 950 cm−1. The blue 

bar also contains barite with characteristic overtones at 2,063, 2,136, and 

1,965 cm−1; traces of zinc stearates; and hydrated magnesite. 

19 See note 12.

20. 3Cu(AsO2

)2Cu(CH3COO)2.

21. General formula CuHAsO3

.

22. The XRF detection of Co and P and a complex convolution of bands between 710 and 1,171 cm−1 shown by reflectance FTIR are consistent with 

cobalt phosphates mixed with an ultramarine underlayer. Point areas analyzed with FORS by John Delaney and Kate Dooley (National Gallery of Art, 

Washington D.C.) highlighted the presence of cobalt blue, possibly used to 

darken the hue or present in adulteration with ultramarine blue. Cobalt blue 

was described in the Russian technical literature on paints as an excellent 

permanent blue pigment, an important pigment to be included in the modern palette; however, because of its cost, colormen often adulterated cobalt 

pigments with ultramarine blue. See Fedor Rerberg, Palitra sovremennogo 

khudozhnika (Moscow: Gosizdat, 1921), 43. 

23. The detection of ultramarine blue by reflectance FTIR and cobalt blue by 

FORS led to the creation of mockups demonstrating that a layered system 

with ultramarine blue below and cobalt violet above would give spectra consistent with the ones recorded in situ on the painting. Technical analysis of 

Malevich’s other Suprematist works ca. 1915–1917 has also revealed that 

the artist often used a multilayering technique to achieve certain colors and 

textures. See Kokkori, “Russian Avant-Garde Art.”

24. Fedor Rerberg, Kraski i drugie khudozhestvennye sovremennye materialy 

(Moscow: Izd. Moskovskago tovarishchestva khudozhnikovʹ, 1905), 19–20.

25. Aleksandr Blok, Polnoe sobranie stikhotvorenii v trekh tomakh (Moscow: 

Progress-Pleiada, 2009–2011).

26. Vladimir Mayakovsky, Parizh (Moscow: Moskovskii rabochii, 1925).

27. During the 1950s, while on deposit at the Stedelijk Museum, all of Malevich’s 

paintings were wax lined and varnished, as was common practice at the time. 

The synthetic varnish has since been removed from the surface. For more 

about Malevich surface appearances, see Louise Wijnberg, “Do We See What 

We Know or Do We Know What We See? Conservation of Oil Paintings in 

the Stedelijk Museum Amsterdam,” in Issues in Contemporary Oil Paint, ed. 

Klaas Jan van den Berg, Aviva Burnstock, Matthijs de Keijzer, Jay Krueger, 

Tom Learner, Alberto de Tagle, and Gunnar Heydenreich (Cham, Switzerland: Springer, 2014), 21–23. 

28. Malevich, Ot kubizma i futurizma k suprematizmu, 11.

29. For further discussion on faktura, see Vladimir Markov, Printsipy tvorchestva 

v plasticheskikh iskusstvakh: faktura (Petrograd: Izdanie Obshchestva Khudozhnikov ‘Soiuz Molodezhi’, 1914); Aage Hanse-Löve, “Faktura, Fakturnost,” Russian Literature 17, no. 1 (1985): 29–38; Benjamin H. D. Buchloh, 

“From Faktura to Factography,” October 30 (Autumn1984): 82–119, http://

dx.doi.org/10.2307/778300; Maria Gough, “Faktura: The Making of the 

Russian Avant-Garde,” RES: Anthropology and Aesthetics 36 (Autumn 

1999): 32–59; Alexander Bouras, “Faktura utopii,” in “Khudozhestvennaia 

tekhnika i materialyv teorii i praktike russkogo avangarda” (Ph.D. thesis, 

Moscow Architectural Institute, 2016).

30. F. Rosi, C. Miliani, C. Clementi, K. Kahrim, F. Presciutti, M. Vagnini, 

V. Manuali, A. Daveri, L. Cartechini, B. G. Brunetti, and A. Sgamellotti, “An 

Integrated Spectroscopic Approach for the Non-invasive Study of Modern 

Art Materials and Techniques,” Applied Physics A 100, no. 3 (2010): 613–

624, http://dx.doi.org/10.1007/s00339-010-5744-7.

31. F. Rosi, A. Burnstock, K. J. Van den Berg, C. Miliani, B. G. Brunetti, and 

A. Sgamelotti, “A Non-invasive XRF Study Supported by Multivariate 

Statistical Analysis and Reflectance FTIR to Assess the Composition of 

Modern Painting Materials,” Spectrochimica Acta A 71, no. 5 (2009): 1655–

1662, http://dx.doi.org/10.1016/j.saa.2008.06.011.

32. C. Miliani, K. Kahrim, B.G. Brunetti, A. Sgamellotti, A. Aldrovandi, M. R. 

van Bommel, K. J. van den Berg, and H. Janssen, “MOLAB, a Mobile Facility 

Suitable for Non-invasive in-Situ Investigations of Early and Contemporary 

Paintings: The Case-Study of Victory Boogie Woogie (1942–1944) by Piet 

Mondrian,” in ICOM Committee for Conservation 15th Triennial Meeting, 

New Delhi, 22–26 September 2008, ed. Janet Bridgland (New Delhi: Allied 

Publishers, 2008), 857–864.

33. C. Miliani, F. Rosi, A. Burnstock, B. G. Brunetti, and A. Sgamelotti, “Noninvasive in-Situ Investigations Versus Micro-sampling: A Comparative Study 

on a Renoirs Painting,” Applied Physics A 89, no. 4 (2007): 849–856.

34. L. Monico, F. Rosi, C. Miliani, A. Daveri, and B. Brunetti, “Non-invasive 

Identification of Metal-Oxalate Complexes on Polychrome Artwork Surfaces by Reflection Mid-infrared Spectroscopy,” Spectrochimica Acta Part A: 

Molecular and Biomolecular Spectroscopy 116 (December 2013): 270–280, 

http://dx.doi.org/10.1016/j.saa.2013.06.084. 

35. M. Alfeld, J. V. Pedroso, M. V. Hommes, G. Van der Snickt, G. Tauber, 

J. Blaas, M. Haschke, K. Erler, J. Dik, and K. Janssens, “A Mobile Instrument for in Situ Scanning Macro-XRF Investigation of Historical Paintings,” 

Journal of Analytical Atomic Spectrometry 28, no. 5 (2013): 760–767, http://

dx.doi.org/10.1039/c3ja30341a.

36. J. K. Delaney, J. G. Zeibel, M. Thoury, R. Littleton, M. Palmer, K. M. Morales, E. R. de la Rie, and A. Hoenigswald, “Visible and Infrared Imaging 

Spectroscopy of Picasso’s Harlequin Musician: Mapping and Identification of 

Artist Materials in Situ,” Applied Spectroscopy 64 (2010): 584–594, http://

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Mondrian.” In ICOM-CC 15th Triennial Conference New Delhi, 22–26 September 2008, ed. Janet Bridgland, pp. 857–864. New Delhi: Allied Publishers, 

2008.

Miliani, C., F. Rosi, A. Burnstock, B. G. Brunetti, and A. Sgamelotti. “Non-invasive 

in-Situ Investigations Versus Micro-sampling: A Comparative Study on a 

Renoirs Painting.” Applied Physics A 89, no. 4 (2007): 849–856. http://dx

.doi.org/10.1007/s00339-007-4222-3.

Miliani, C., F. Rosi, A. Daveri, and B. G. Brunetti. “Reflection Infrared Spectroscopy for the Non-invasive in Situ Study of Artists’ Pigments.” Applied 

Physics A 106, no. 2 (2012): 295–307. http://dx.doi.org/10.1007/s00339

-011-6708-2.

Monico, L., F. Rosi, C. Miliani, A. Daveri, and B. Brunetti. “Non-invasive Identification of Metal-Oxalate Complexes on Polychrome Artwork Surfaces by 

Reflection Mid-infrared Spectroscopy.” Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 116 (December 2013): 270–280. http://

dx.doi.org/10.1016/j.saa.2013.06.084.

Rerberg, Fedor. Kraski i drugie khudozhestvennye sovremennye materialy. Moscow: Izd. Moskovskago tovarishchestva khudozhnikovʹ, 1905.

———. Palitra sovremennogo khudozhnika. Moscow: Gosizdat, 1921.

Rosi, F., A. Burnstock, K. J. Van den Berg, C. Miliani, B. G. Brunetti, and 

A. Sgamelotti. “A Non-invasive XRF Study Supported by Multivariate Statistical Analysis and Reflectance FTIR to Assess the Composition of Modern 

Painting Materials.” Spectrochimica Acta A 71, no. 5 (2009): 1655–1662. 

http://dx.doi.org/10.1016/j.saa.2008.06.011. 

Rosi, F., C. Miliani, C. Clementi, K. Kahrim, F. Presciutti, M. Vagnini, V. Manuali, 

A. Daveri, L. Cartechini, B. G. Brunetti, and A. Sgamellotti. “An Integrated 

Spectroscopic Approach for the Non-Invasive Study of Modern Art Materials 

and Techniques.” Applied Physics A 100, no. 3 (2010): 613–624. http://dx

.doi.org/10.1007/s00339-010-5744-7. 

Vagnini, M., C. Miliani, L. Cartechini, P. Rocchi, B. G. Brunetti, and. A. Sgamellotti. 

“FT-NIR Spectroscopy for Non-invasive Identification of Natural Polymers 

and Resins in Easel Paintings.” Analytical and Bioanalytical Chemistry 395, 

no. 7 (2009): 2107–2118. http://dx.doi.org/10.1007/s00216-009-3145-6.

Vikturina, Milda, and Alla Lukanova. “A Study of Technique: Ten Paintings by 

Malevich in the Tretiakov Gallery.” In Kazimir Malevich, 1878–1935, pp. 

187–197. Los Angeles: Armand Hammer Museum of Art and Cultural Center, 

1990.

Wijnberg, Louise. “Do We See What We Know or Do We Know What We See? 

Conservation of Oil Paintings in the Stedelijk Museum Amsterdam.” In Issues in Contemporary Oil Paint, ed. Klaas Jan van den Berg, Aviva Burnstock, Matthijs de Keijzer, Jay Krueger, Tom Learner, Alberto de Tagle, and 

Gunnar Heydenreich, pp. 21–23. Cham, Switzerland: Springer, 2014.

Page numbers in italics indicate tables and figures.

Aachener Nachrichten (newspaper), 49n15

Acts of John, 49n8

Altarpiece of the Saints John (Martorell), 39

altarpieces

Andalusia, 43

Aragon, 37, 41, 43, 48, 49n11

Castile, 41, 42

Catalonia, 37, 39, 41, 48, 49n11

construction techniques, 40–42, 49n30

terminology, 39, 49n14

Valencia, 37, 41, 42, 43, 48

Andalusia, altarpiece construction, 43

Anna Přemyslid, Duchess of Breslau, 26–27

Aragon, altarpiece construction, 37, 41, 43, 48, 49n11

Art Institute of Chicago, 66

avant-garde art, 72

Barnes Foundation, Philadelphia. see Le Bonheur de vivre (Matisse)

Beeby, Andrew, 35n5

The Beheading of St. John the Baptist and the Feast of Herod (panel painting), 37–51, 38f

assembly technique, 41–42, 49n23

attribution, 37, 44–45, 48

binding media and surface appearance, 44–45, 50nn48–49

conservation treatments, 37, 46t

dating, 45

dorado (gilding), 44, 45f

frame, 39, 49n9

Fourier transform infrared spectroscopy analysis, 42, 43, 49nn33–34, 50n39

iconography, 39

image size, 41

infrared reflectography analysis, 43, 50n44

layer buildup, 42–43, 50n38

methods of analysis, 42, 49nn33–34

noninvasive and microinvasive techniques, 42, 49nn33–34

paint layers, 45–48

panel construction, 39–41

pigment analysis, 42, 46t

preparatory layers, 42–43

portable X-ray fluorescence spectroscopy analysis, 42, 44, 45, 46t

scanning electron microscopy with back scattered electrons analysis, 42, 43, 43f

Index
7 8 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

The Beheading of St. John the Baptist and the 

Feast of Herod (panel painting) (continued)

scanning electron microscopy-energy dispersive X-ray spectroscopy analysis, 42, 

43, 44, 46–47, 47f, 49n34, 50n40

structural examination, 39–42

support construction, 39, 40–41

technical investigation, 42, 49nn33–34, 

50nn38–40

underdrawing and incised lines, 43–44

Beissel, Louis (Ludwig), 37, 49n3

Black Square (Malevich), 66

Blok, Aleksandr, 72

Boccioni, Umberto, 67

Boguslavskaia, Ksenia, 65

Le Bonheur de vivre (Matisse), 55f

alteration products, 60

cadmium yellow alteration in, 53, 54–56

detail, 58f

longwave ultraviolet illumination, 59f

multispectral imaging, 57, 58, 59f, 60, 64

portable X-ray fluorescence spectroscopy 

analysis, 58

related works, 54–55

ultraviolet-induced infrared fluorescence, 

57, 58, 58f

ultraviolet-induced visible fluorescence, 

57–58, 58f, 59f, 63

Breslau Psalter, 25–36

analytical protocol, 26–31

art historical analysis, 26, 27–29

artists, 27–29, 31t, 32t, 33–35, 33f, 34f,

35–36nn11–17

B(eatus) initial, 27–28, 27f

codicological analysis, 26, 29

conclusions, 35

dating and localization, 26–27

“Digital Layers” project, 36n18

Fiber-optic reflectance spectroscopy 

analysis, 26, 29, 31, 32f, 33f, 34f, 35n8, 

35n10

Fourier transform infrared spectroscopy 

analysis, 35n11

historiated initials, 27–28, 27f, 31t

idiosyncrasies, 34, 36n17

illuminations, 25, 27f, 28f, 30f, 31t, 32f,

34f

micrographs, 34f

near-infrared hyperspectral imaging, 35n11

overview, 26

paint binders, 31, 35, 35n13

paleographical analysis, 26–27

pigment analysis, 31, 32t, 33, 35nn9–11, 

35n16

previous literature, 35n4

quires, 29, 31t

Raman spectroscopy, 26, 31

reflectance spectroscopy, 29, 31

technical investigation, 29, 31

textual analysis, 26–27

X-ray diffraction analysis, 26, 35n5

X-ray fluorescence analysis, 26, 31, 35n5

cadmium yellow alteration, 53–64

in early modernist works, 53, 54

longwave ultraviolet illumination, 59f, 60, 

61f, 63

multispectral imaging, 53, 57, 58, 59f, 60, 64

and paint mixture, 60, 63

photodegradation, 53, 54, 60, 63

portable X-ray fluorescence spectroscopy 

analysis, 53, 57, 58, 60, 63

ultraviolet-induced infrared fluorescence, 

53, 57, 58, 58f, 60, 61f, 62f, 63, 64

ultraviolet-induced visible fluorescence, 53, 

56–58, 58f, 59f, 60, 61f, 62f, 63–64

X-ray fluorescence analysis, 53, 57, 60

canvas paintings. see induced strain in canvas 

paintings

Castile, altarpiece construction, 41, 42

Catalonia, altarpiece construction, 37, 39, 

41, 48, 49n11

CHARISMA-MOLAB (Cultural Heritage 

Advanced Research Infrastructures: Synergy for a Multidisciplinary Approach 

to Conservation and Restoration—Mobile Laboratory) project, 35n5

climate control. see environmental conditions

conservation treatment. see also organic 

solvent treatments; varnishing; varnish 

removal

The Beheading of St. John the Baptist and 

the Feast of Herod (panel painting), 37, 

46t

illuminated manuscripts, 25, 35n1

Malevich’s paintings, 74n27

St. John the Evangelist Drinking from a 

Poisoned Chalice (panel painting), 37, 

45, 47, 49n15, 50n54

Constructivists, 72

cracks in paintings

“age” cracks, 18, 19f

strain pattern, 10–11

Creemers, Jos, 49n17

“CSI Aachen: Unraveling the History of Two 

Fifteenth Century Spanish Panels Using 

Forensic Methodologies,” 48n1

Cubo-Futurism, 72

Cultural Heritage Advanced Research 

Infrastructures: Synergy for a Multidisciplinary Approach to Conservation 

and Restoration—Mobile Laboratory 

(CHARISMA-MOLAB) project, 35n5

The Dance (artist unknown), 15–23, 17f

canvas stiffness, 20

condition of, 18, 19f

date, 18

energy-dispersive x-ray spectroscopy 

analysis, 18

infrared reflectography analysis, 18

paint stiffness, 18–19

paint surface details, 19f

restretching, 18

scanning electron microscopy analysis, 18, 

19f

signal profile, 18, 20f, 23n8

size, 16

thickness, 23n7

treatment-induced changes, 22

Delaney, John, 74n22

de la Rie, R., 56

“Digital Layers” project, 36n18

The Dinner (artist unknown), 15–23, 17f

“age” cracks, 18, 19f

canvas stiffness, 20

condition of, 18, 19f

date, 18

energy-dispersive x-ray spectroscopy 

analysis, 18

infrared reflectography analysis, 18

overpainting, 18

paint stiffness, 19

paint surface details, 19f

restretching, 18

scanning electron microscopy analysis, 18, 

19f

signal profile, 20f, 23n9

size, 16

thickness, 23n7

varnishing, 18, 19

Dooley, Kate, 74n22

Du “Cubisme” (Gleizes and Metzinger), 66–67

Durham University, 35n5

Dynamism of a Soccer Player (Boccioni), 67

early modernist paintings, cadmium yellow 

alteration, 53, 54

El Greco, Velázquez, Goya: Five Centuries 

of Spanish Masterpieces (exhibition), 

37–38, 48

energy-dispersive x-ray spectroscopy (EDX), 18

Ensor, James, 54

environmental conditions

cadmium yellow alteration, 54

induced strain on canvas paintings, 1, 9, 10f

production of lower-molecular-weight 

species, 19

Esquisse pour “Le Bonheur de vivre”

(Matisse), 54–56, 55f

longwave ultraviolet illumination, 60, 

61f, 63

portable X-ray fluorescence spectroscopy 

analysis, 60

ultraviolet-induced infrared fluorescence, 

57, 60, 63

ultraviolet-induced visible fluorescence, 60, 

61f

varnish removal, 60

exhibition conditions. see environmental 

conditions

faktura (texture), 72

fast Fourier transform (FFT), 4–5, 4f

fiber-optic reflectance spectroscopy (FORS)

Breslau Psalter, 26, 29, 31, 32f, 33f, 34f,

35n8, 35n10

Football Player (Malevich), 70, 74nn22–23

instruments, 35n8

Firmierung Draht-Fabrik-Compagnie, 

Aachen, 49n3

Football Player (Malevich), 65–75, 66f

black paint, 71, 74n17

blue paint, 71, 74n18, 74nn22–23

condition, 72
NUMBER 5 • 7 9

details, 70f

fiber-optic reflectance spectroscopy analysis, 70, 74nn22–23

Fourier transform infrared spectroscopy 

analysis, 65, 67, 67t, 70–72, 71f, 72f,

73, 73n14, 74nn16–18, 74nn22–23

green paint, 71

ground layer, 70, 73n14

historical context, 66–67

infrared reflectography analysis, 65, 68, 

69f, 71

orientation, 73n10

painting techniques and materials, 68–70, 

70f

provenance, 66

red paint, 71

surface and facture, 72

technical examination and scientific 

analysis, 67

title, 66–67

ultraviolet-induced visible fluorescence, 65, 

68–69, 69f

violet paint, 71–72, 72f, 74nn22–23

white paint composition, 70, 71f, 73n15

X-ray fluorescence analysis, 65, 67, 67t,

68, 68f, 69, 70–71, 73, 73n13, 74n22

yellow paint, 70–71

Formalist theorists, 72

FORS. see fiber-optic reflectance spectroscopy

FORTH (Foundation for Research and 

Technology–Hellas), 2

Foundation for Research and Technology–

Hellas (FORTH), 2

Fourier transform–based methods

shearography, 3, 4

2-dimenional fast Fourier transformation, 

4–5, 4f

Fourier transform infrared spectroscopy 

(FTIR)

Breslau Psalter, 35n11

Football Player (Malevich), 65, 67, 67t,

70–72, 71f, 72f, 73, 73n14, 74nn16–18, 

74nn22–23

Fourier transform infrared spectroscopy–

attenuated total reflectance (FTIR-ATR)

instruments, 49n33, 50n39

panel paintings, 42, 43, 49nn33–34, 50n39

fourth-dimensional space, 67

Fries Museum, Leeuwarden, Netherlands, 

16, 18

fringe patterns, 2, 3

FTIR. see Fourier transform infrared 

spectroscopy

FTIR-ATR. see Fourier transform infrared 

spectroscopy–attenuated total reflectance

Futurist poets, 72

Gabo, Naum, 66

Gaibana Master (Giovanni da Gaibana), 

27–29, 33, 34, 35, 35n11, 35n15

Getty Conservation Institute, 36n18

Gleizes, Albert, 66–67

Gogh, Vincent van, 54

Greco, Velázquez, Goya (exhibition catalog), 

37–38, 48

Grosse Berliner Kunstausstellung (Great Art 

Exhibition), Berlin, Germany, 66

Hamilton Kerr Institute (HKI), 45–46

Häring, Hugo, 66

Helen, Duchess of Breslau, 26–27

Henry II, Duke of Breslau, 26–27

Henry III, Duke of Breslau, 26–27

Hinton, Howard, 67

HKI (Hamilton Kerr Institute), 45–46

holographic interferometry, vii, 1–2

Huguet, Jaume, 48

humidity, 9

illuminated manuscripts. see also Breslau 

Psalter

conservation treatments, 25, 35n1

discussion, 33–34

introduction, 25–26

noninvasive analysis, need for, 26, 35n2

Impressionist paintings, cadmium yellow 

alteration, 53

induced strain in canvas paintings

causative factors, 1, 9

components, 3

cracks in paintings, 10–11

quantifying and mapping with laser 

shearography, 1–13

infrared fluorescence. see ultraviolet-induced 

infrared fluorescence

Infrared Users Group (IRUG) database, 

50n39

Institute for Technical Optics, Stuttgart 

University, 2

Institute of Electronic Structure and Laser–

FORTH, 2

International Council of Museums–Committee for Conservation, 48n1

infrared digital photography, 43, 50n44

IR reflectography. see infrared reflectography 

IRR. see infrared reflectography

infrared reflectography (IRR)

The Dance, 18

The Dinner, 18

Football Player (Malevich), 65, 68, 69f, 71

instruments, 50n44

panel paintings, 43, 50n44

IRUG (Infrared Users Group) database, 50n39

Isabella of Portugal, 44–45

John the Baptist, St. see The Beheading of St. 

John the Baptist and the Feast of Herod

(panel painting)

John the Evangelist, St. see also St. John the 

Evangelist Drinking from a Poisoned 

Chalice (panel painting)

companion and disciple, 49n8

retablos and altarpieces dedicated to, 39

The Joy of Life (Matisse). see Le Bonheur de 

vivre (Matisse)

Kan, Paul van, 50nn39–40

Khlebnikov, Velimir, 65

Klein, Peter, 49n16

Kruchenykh, Aleksei, 65

Laboratoire d’Archéologie Moléculaire et 

Structurale, Paris, 35n5

Landscape near Collioure (Matisse), 54, 55f,

56, 57, 60

laser shearography. see shearography

Leger, Fernand, 54

Leone, B., 54

Leucius Charinus, 49n8

Liauckamastate, Friesland, Netherlands, 18

lighting, and strain on canvas paintings, 9, 10f

lithopone extenders, 70, 73n15

longwave ultraviolet illumination, 59f, 60, 

61f, 63

lower-molecular-weight (LMW) components, 

19–20

Lunder Conservation Center, 48n1

Malevich, Kazimir. see also Football Player

(Malevich)

Black Square, 66

conservation treatments of his paintings, 

74n27

Cubo-Futurist works, 72

faktura (texture), 72

orientation of paintings, 67, 73n10

Suprematist period, 65–68, 72, 73n10

zaum experiments, 65

0.10 (Zero–Ten): The Last Futurist Exhibition of Painting, 65–66, 67

Manuscript Illumination: Non-Invasive 

Analysis, Research and Expertise 

(MINIARE) research project, 35n4

manuscripts. see illuminated manuscripts

Martorell, Bernat, 39

Matisse, Henri, paintings by. see Le Bonheur 

de vivre; Esquisse pour “Le Bonheur de 

vivre”; Landscape near Collioure

Mayakovsky, Vladimir, 72

Metzinger, Jean, 66–67

Michelson interferometer, 2

Mies van der Rohe, Ludwig, 66

MINIARE (Manuscript Illumination: NonInvasive Analysis, Research and Expertise) research project, 35n4

multispectral imaging

cadmium yellow alteration, 53, 57, 58, 

59f, 60, 64

efficiency and comprehensive nature of, 60

instruments, 57

Munch, Edvard, paintings by. see The Scream

Munch Museum, Oslo, 53, 56, 57

Museo Nacional del Prado, Madrid, 49n30

Museum of Fine Arts, Budapest, 37–38, 48

Museum of Fine Arts, Valencia, 41

National Museum of Catalan Art, 

Barcelona, 41

near-infrared hyperspectral imaging, 35n11

Nicholson, Kate, 35n5

NMR. see nuclear magnetic resonance

“The Non-Invasive Analysis of Painted Surfaces: Scientific Impact and Conservation Practice” (conference), vii, 48n1

nuclear magnetic resonance (NMR), and 

organic solvent treatments, 15–23
8 0 • SMITHSONIAN CONTRIBUTIONS TO MUSEUM CONSERVATION

nuclear magnetic resonance (NMR) (continued)

analytical methods, 16

chemical shifts, 16

experimental overview, 16, 18

hardness of material, 16

model paint sample, 18, 20–22, 20f

relaxation rates, 16

signal profiles, 16, 18, 20–22, 21f

organic solvent treatments, 15–23. see also

varnishing; varnish removal

analytical methods, 16

experimental overview, 16, 18

lower-molecular-weight components, 20

previous studies, 23n1

Pacheco, Francisco, 43, 44, 48

Padua Cathedral, 27

Painterly Realism of a Football Player

(Malevich). see Football Player

(Malevich)

paleographical analysis, 26

panel paintings. see The Beheading of St. 

John the Baptist and the Feast of Herod

(panel painting); St. John the Evangelist Drinking from a Poisoned Chalice

(panel painting)

Philip the Good, Duke of Burgundy, 44–45

photomicroscopy, 26

Picasso, Pablo, 54

pigment analysis. see also cadmium yellow 

alteration

Breslau Psalter, 31, 32t, 33, 35nn9–11, 

35n16

Football Player (Malevich), 70–72, 71f,

72f, 73n15, 74nn17–18, 74nn22–23

panel paintings, 42, 45–47, 46t, 47f

Pipenpoyse Wedding (artist unknown), 

15–23. see also The Dance; The Dinner

portable X-ray fluorescence spectroscopy 

(pXRF)

cadmium yellow alteration, 53, 57, 58, 

60, 63

instruments, 57

panel paintings, 42, 44, 45, 46t

Psalms. see Breslau Psalter

Puni, Ivan, 65

pXRF. see portable X-ray fluorescence 

spectroscopy

Raman spectroscopy analysis, 26, 31, 35n5, 

70

realism, 67

reflectance Fourier transform infrared spectroscopy. see Fourier transform infrared 

spectroscopy

reflectance spectroscopy, 29, 31

reflectance transformation imaging (RTI), 1, 

10–11, 11f, 12f

Reixach, Juan, 48

relative humidity, 9

Rerberg, Fedor, 72

resin varnishes. see varnishing; varnish 

removal

Rousselière, Hélène, 35n5

RTI. see reflectance transformation imaging

San Francisco Museum of Modern Art, 53, 

54–56, 60, 61f

Santa Marina retablo, 45–46

scanning electron microscopy (SEM), 18, 19f

scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS)

instruments, 50n40

panel paintings, 42, 43, 44, 46–47, 47f,

49n34, 50n40

scanning electron microscopy with backscattered electrons (SEM-BSE), 42, 43, 43f

The Scream (Munch), 55f

cadmium yellow alteration, 53, 56

portable X-ray fluorescence spectroscopy 

analysis, 63

ultraviolet-induced infrared fluorescence, 

57, 62f, 63, 64

ultraviolet-induced visible fluorescence, 56, 

62f, 63

SEM (scanning electron microscopy), 18, 19f

SEM-BSE. see scanning electron microscopy 

with backscattered electrons

SEM-EDS. see scanning electron microscopyenergy dispersive X-ray spectroscopy

Seurat, Georges, 54

shearography, 1–13

automatic shear estimation algorithm, 4f, 5

calibration of measurement sensitivity, 4–5

camera, 5–7

controlled temperature excitation testing, 

7–8

correlating shearography data to topographical features, 9–11

cost of instrument, 6

data processing, 9

deformation, 4, 8

displacement gradients, 8, 8f, 9, 11, 11f, 12f

gallery lighting, effect of, 9, 10f

holographic interferometry comparisons, 1–2

instrument, 2f, 5–6, 5f, 6f

in situ gallery tests, 8–9

interferogram, 2, 3

laser specifications, 5, 6

microstrains, 7, 7f

optical phase changes, 3–4

optical setup, 2–3, 2f

principles and methods, 2–5

reflectance transformation imaging analysis, 1, 10–11, 11f, 12f

strain maps, 9, 9f, 10f, 12f

surface temperature of painting, 7

test setup, 5–7, 5f

transient response to thermal loading, 7f

2-dimenional fast Fourier transformation 

of shearogram, 4f

single-sided nuclear magnetic resonance. see

nuclear magnetic resonance (NMR), 

and organic solvent treatments

Sketch for Le Bonheur de vivre (Matisse). see

Esquisse pour “Le Bonheur de vivre”

(Matisse)

Spain, church construction, 49n18

Spanish panel paintings. see The Beheading 

of St. John the Baptist and the Feast of 

Herod; St. John the Evangelist Drinking 

from a Poisoned Chalice

State Institute for Artistic Culture in Petrograd (GINKhUK), 66

Statens Museum for Kunst, Copenhagen, 53, 

54, 56, 57, 60

Stedelijk Museum, Amsterdam, 66, 74n27

Stichting Restauratie Atelier Limburg (SRAL)

The Dinner and The Dance, 15, 16, 17f,

18, 23n8

panel painting analysis, 37, 42, 49n28, 

49n32, 50n44

St. John the Baptist (panel painting). see The 

Beheading of St. John the Baptist and 

the Feast of Herod

St. John the Evangelist Drinking from a 

Poisoned Chalice (panel painting), 

37–51, 38f

assembly technique, 41–42, 49n23

attribution, 37–38, 44–45, 48

binding media and surface appearance, 

44–45, 50nn48–49

conservation treatments, 37, 45, 47, 49n15, 

50n54

dating, 45

dorado (gilding), 44, 45f

frame, 39, 49n9

Fourier transform infrared spectroscopy 

analysis, 42, 43, 49nn33–34, 50n39

iconography, 39

image size, 41

incised lines, 43–44, 50n46

infrared digital photography, 43, 50n44

infrared reflectography analysis, 43, 50n44

layer buildup, 42–43, 43f, 46, 50n38

methods of analysis, 42, 49nn33–34

noninvasive and microinvasive techniques, 

42, 49nn33–34

paint layers, 45–48

panel construction, 39–41

pigment analysis, 42, 45–47, 46t, 47f

preparatory layers, 42–43

portable X-ray fluorescence spectroscopy 

analysis, 42, 44, 45, 46t

reverse, detail of, 42f

scanning electron microscopy with back 

scattered electrons analysis, 42, 43, 43f

scanning electron microscopy-energy dispersive X-ray spectroscopy analysis, 42, 

43, 44, 46–47, 47f, 49n34, 50n40

structural examination, 39–42

stylistic attribution, 48

support construction, 39–42, 40f,

49nn15–17

technical investigation, 42–43, 43f,

49nn33–34, 50nn38–40

title, 48n2

underdrawing, 43–44

X-radiography, 41, 49n28

strain in canvas paintings. see induced strain 

in canvas paintings
NUMBER 5 • 8 1

Stuttgart University, Institute for Technical 

Optics, 2

Suermondt, Robert Frederick, 37

Suermondt-Ludwig-Museum, Aachen, 37, 

48n2, 49nn4–5, 49nn15–16. see also

The Beheading of St. John the Baptist

and the Feast of Herod; St. John the 

Evangelist Drinking from a Poisoned 

Chalice

Suprematism, 65–68, 72, 73n10

surface cracks in paintings, 10–11

Szépmuvészeti Múzeum, Budapest, 

37–38, 48

temperature, gallery, 9, 10f

textual analysis, Breslau Psalter, 26

Thyssen, Johann Friedrich, 49n3

Thyssen-Bornemisza, Baron Hans Heinrich, 

49n3

Thyssen-Bornemisza Museum, Madrid, 

49n3

topography, of painting’s surface, 9–11

Tornari, V., 2

transport of paintings, 2

treatments. see conservation treatment; 

organic solvent treatments; varnishing; 

varnish removal

Truyen, Arnold, 49n28

2-dimensional fast Fourier transform (FFT), 

4–5

Uffelman, Erich S., 23n6, 49nn32–33, 50n44

ultraviolet illumination. see longwave ultraviolet illumination

ultraviolet-induced infrared fluorescence

cadmium yellow alteration, 53, 57, 58, 

58f, 60, 61f, 62f, 63, 64

instruments, 57

ultraviolet-induced visible fluorescence

cadmium yellow alteration, 53, 56–58, 

58f, 59f, 60, 61f, 62f, 63–64

Football Player (Malevich), 65, 68–69, 69f

instruments, 56, 57

unwrapping algorithms, 4, 9, 11

Uspenskii, Peter, 67

Valencia, altarpiece construction, 37, 41, 42, 

43, 48

Van der Snickt, G., 54, 63

van Gogh, Vincent, 54

varnishing

The Dinner (artist unknown), 15, 18, 19

Malevich’s paintings, 74n27

panel paintings, 44

reasons for reapplication of varnish, 16

resin residue, 20, 22

side effects, 22

varnish removal

1-methoxy-2-propanol, 18

considerations, 20

The Dinner (artist unknown), 15, 19

Esquisse pour “Le Bonheur de vivre”

(Matisse), 60

free solvent, 20–22, 21f, 23n10

increased penetration of resin residues, 20

Malevich’s paintings, 74n27

reasons for, 16

side effects, 16, 20–21, 22

solvent penetration, 22

swab technique, 22

techniques, effect on paint, 20–22, 21f,

23n10

thickened solvent, 20–22, 21f, 23n10

Verlaine and Cézanne (Mayakovsky), 72

Vladislav, archbishop of Salzburg, 26–27

Walter, Philippe, 35n5

Washington and Lee University, 49n32

Weirich, Helmut, 49n15

Worcester Art Museum, 8–9

Worcester Polytechnic Institute (WPI), 5, 

6, 11

X-radiography, 41, 49n28

n-X-ray absorption near edge spectroscopy, 54

X-ray diffraction (XRD), 26, 35n5

X-ray fluorescence (XRF). see also portable 

X-ray fluorescence

Breslau Psalter, 26, 31, 35n5

cadmium yellow alteration, 53, 57, 60

The Dance, 18

The Dinner, 18

Football Player (Malevich), 65, 67, 67t,

68, 68f, 69, 70–71, 73, 73n13, 74n22

Zaragoza, 49n11

zaum, 65, 73n1

0.10 (Zero–Ten): The Last Futurist Exhibition of Painting, 65–66, 67

zinc yellow, 54
SUMMARY OF REQUIREMENTS FOR SMITHSONIAN CONTRIBUTIONS SERIES

For comprehensive guidelines and specifications, visit www.scholarlypress.si.edu. 

ABSTRACTS must not exceed 300 words. 

TEXT must be prepared in a recent version of Microsoft Word; use a Times font in 12 point for regular text; be double 

spaced; and have 1” margins. 

REQUIRED ELEMENTS are title page, abstract, table of contents, main text, and references.

FIGURES must be numbered sequentially (1, 2, 3, etc.) in the order called out; have components lettered consistently (in 

size, font, and style) and described in captions; include a scale bar or scale description, if appropriate; include any legends 

in or on figures rather than in captions. Figures must be original and must be submitted as individual TIF or EPS files.

FIGURE FILES must meet all required specifications in the Digital Art Preparation Guide. Color images should be 

requested only if required. 

TAXONOMIC KEYS in natural history manuscripts should use the aligned-couplet form for zoology. If cross referencing 

is required between key and text, do not include page references within the key, but number the keyed-out taxa, using the 

same numbers with their corresponding heads in the text.

SYNONYMY IN ZOOLOGY must use the short form (taxon, author, year:page), with full reference at the end of the 

manuscript under “References.”

REFERENCES should be in alphabetical order, and in chronological order for same-author entries. Each reference should 

be cited at least once in main text. Complete bibliographic information must be included in all citations. Examples of the 

most common types of citations can be found at SISP’s website under Resources/Guidelines.