# Authentication of a Painting by [PERSON] Using Modern Multi-Analytical Methods
## 4 Conclusions  
Based on the data obtained, the following conclusions are presented:  
* The painting is made by [PERSON], in 1886-1888 period, and corresponds to the age of the painting materials and the support. The framing system and the re-varnishing intervention are subsequent to the artwork's elaboration.
* The painting has an insignificant lack of pictorial material and extended ageing cracks are visible only in small areas of white flower petals;
* The pictorial materials were identified by EDX and \(\upmu\)-FTIR, and in the analysis the most representative oil colors were white, blue, red, and yellow, together with the cardboard support;
* It was established by static and dynamic reflectography in different light sources (visible, white-green, UV, and IR) and by graphoscopy, that the painter's signature and [PERSON]'s authentication writing, are original;
* The authentication of the painting was done by determining the evolution of archaeometric and chemometric characteristics, with archaeometric value, identified in SEM microphotographs and from data obtained by EDX and \(\upmu\)-FTIR, following the surface and cross-section analysis of some representative micro-samples of pictorial materials and support;
* Among the archaeometric (evolutionary) characteristics from SEM microphotographs, analyzed in cross section for the fractal area, two allowed the evaluation of the painting's age, namely: the gradient of the porosity of the pictorial layers and of the varnish, respectively, the degree of the penetration of the pigments in the varnish and of the oxidatively fouled dirt from the surface in the volume phase of the pictorial materials, as being of 250 \(\upmu\)m for the white pigments, 130-260 \(\upmu\)m for blue, 50-130 \(\upmu\)m for red and yellow, and corresponding to an interval of about 130 years (in white the rate is approx. 1.0-2.0 \(\upmu\)m/year, blue 0.2-2.0 \(\upmu\)m/year, red and yellow 0.5-1.0 \(\upmu\)m/year, varnish 0.2-0.5 \(\upmu\)m/year), considering the constant display conditions in the gallery;
* Regarding the chemometric characteristics, the evaluation was made starting from the stoichiometric ratio of the basic congruents, found in the composition of the pictorial materials, namely: Si/Al (caustic modulus of earth colors), which varies between 0.589 and 1.084; C/O (of CO32- ion) approx. 0.25; S/O (of the SO42- ion) approx. 0.5 and Zn/O approx. 4.063;
* Among the chemometric characteristics: C/S, Zn/C, and Zn/S, only the first, which corresponds to the ratio between carbonate and sulfate anions, has a wide range of variation, which allows only the assessment of the degree of mixing between colors when elaborating the work of art, while the others provide information about the degree of carbonation and sulfation, which take place over time, having a good coherence in archaeometric analysis.
* For all four pictorial materials, varnish, and support, the rate of evolution of chemometric characteristics corresponds to an age of about 130 years.  
Conceptualization and project administration P.O.T., methodology and supervision I.S., investigation and data curation V.V., methodology and investigation I.G.S., formal analysis and investigation I.C.N., writing--review and editing and validation A.V.S. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
The authors declare no conflict of interest.