Additional file 1 of Evaluation of novel cleaning systems on mock-ups of unvarnished oil paint and chalk-glue ground within the Munch Aula Paintings Project
Creators: name: Stoveland, Lena Porsmo
name: Frøysaker, Tine
name: Stols-Witlox, Maartje
name: Grøntoft, Terje
name: Steindal, Calin Constantin
name: Madden, Odile
name: Ormsby, Bronwyn
Publisher: name: figshare
Year: 2021
Subjects: subject: Space Science
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Ecology
subject: FOS: Biological sciences
subject: 69999 Biological Sciences not elsewhere classified

description: Additional file 1: Figure S1. a Low-vacuum SEM–EDX of an oil paint from The Sun suggested a cobalt blue pigment (PB28 cobalt aluminate CoO·Al2O2, 2–27 µm) and barium sulfate (probably synthetic, 0.8–3.5 µm) extender in a drying oil-based medium. Greyscale threshold images suggested area fractions of 14–19% of filler to bulk paint (cobalt blue pigment and oil fraction). b Low-vacuum SEM–EDX of a ground from Alma Mater suggested calcium to be the major element, attributed to chalk (CaCO3) (probably manufactured). BSE images suggested spherical chalk particles c. 0.2–4 µm, with most of the particles between 1 and 2 µm. Figure S2. SEM secondary electron image of a polyurethane cleaning sponge (~ 100×) used for the control treatment. Figure S3. SEM secondary electron images of wheat starch, Arbocel® A and Arbocel® B. ~ 300× magnification. Figure S4. Soft particle blasting set-up: oil free air compressor, nozzle with hand switch, air gun with Y-connector, air blaster, blasting cabinet (not shown) and soft abrasives (not shown). Main unit supplier: Deffner &amp; Johann. Stipulated line = connection or continuation. Figure S5. CO2-snow cleaning set-up: dual gas Venturi nozzle, CO2-gas tank with pressure gauge, compressed air heater, foot switch, nitrogen gas (not shown), CO2 detector (not shown), fume hood (not shown). Main unit supplier: Applied Surface Technologies. Stipulated line = connection or continuation. Figure S6. Hydro-gel sheet with detail of high-water-retention nano-gel. Supplier: Center for Colloid and Surface Science. Aqueous cleaning solutions selected from the Modular Cleaning Program. Figure S7. Accelerated aged control mock-ups (M2): unsoiled (upper) and artificially soiled (lower). 60× objective, Hirox RH-2000-3D digital microscope (Hirox Europe, Limonest, France). The soiled mock-ups demonstrate the darkening and mattening effect of soiling. Figure S8. a FTIR spectra of the chalk-glue ground mock-ups before (upper) and at the end (middle spectra) of ageing and bread cleaning procedures, and of the chalk-based ground of Munch’s Alma Mater (lower). The Si–O–Si stretching bands in the Munch sample at 1200–1000 (1190, 1150 and 1090 cm–1) were attributed to trace ultramarine pigments (Na, Al, Si, S confirmed with SEM–EDX). These and traces of Pb and Zn, possibly deriving from small additions of lead and zinc white, were excluded from the mock-up ground to simplify the composition. The band with a maximum at 1030 cm−1 (assigned to SO42– or Si–O–Si stretching) in the spectra of the aged and bread cleaned unsoiled M2-G mock-ups is probably contamination. No corrections to spectra. b Surface ATR-FTIR of M2-Pu mock-ups before (red line) and at the very end (blue line) of ageing and bread cleaning procedures. The black line shows the FTIR spectrum acquired with transmission spectroscopy of a sample of cobalt blue bulk paint and of the blue oil paint from Munch’s The Sun. No corrections to spectra. c Surface ATR-FTIR spectra of the Pd mock-ups before (red line) and at the very end (blue line) of ageing and bread cleaning procedures, and of the blue oil paint of Munch’s The Sun (black line). The spectrum for the Pd mock-up has a weak abortion band at 870 cm–1 attributed to chalk from the ground layer. No corrections to spectra. Figure S9. a Velocity of SPB abrasive powders compared to compressed air alone. Average of ten measurements. Standard deviation as error bars. b Velocity of the CO2-snow stream compared to that of SPB with Arbocel® A. Standard deviation as error bars. Figure S10. a–c Colour measurements1. Figure S11. a–c Gloss measurements2. Figure S12. Performance of cleaning systems on parameters (G–I) related to user-friendliness.