Abstract
Introduction
Analytical results
Conclusions
Acknowledgments
Bibliography

ABSTRACT:
This paper presents the results obtained by non-destructive XRF analyses conducted on six paintings fulfilled to obtain the data base for the pigments used by one of the best known Serbian artists. Paja Jovanovic (1859-1957), is one of the most significant representatives of the Academic Realism in Serbian art at the end of XIX and the beginning of XX century. His work can be found in many European museums.
Paja Jovanovic finished the Academy of Fine Arts in 1877 in Vienna. In response to growing interest of Europe for the Balkans, Jovanovic painted mostly scenes from the life of the Albanians, Montenegrins, Herzegovinians, which won him a lasting reputation (The Wounded Montenegrin, Fencing, Decorating of the Bride, Cockfighting, Migration of Serbs etc). After 1905, he devoted himself exclusively to painting the portraits in the style of Academic Realism, for the wealthy clientele, and he became very famous thanks to his portraiture. He also made the iconostasis in the Dolovo and Saborna churches in Novi Sad. With the aim of studying the variation in his colour palette as he matured as a painter, and for the purpose of verifying the authenticity of many of the paintings that are claimed to be his, under the Technical project of IAEA we have performed the examination of the Paja Jovanovic paintings from the National museum Belgrade using the non destructive technique provided by the transportable EDXRF system. As an aim of the XRF analysis non destructive imaging analyses (X rays, Infrared Reflectography and UV Fluorescence) were also fulfilled. The work in progress results show that Paja Jovanovic had a very rich and multiform palette both in the colours used for painting and in the ground layers. In this work we are going to present the diversity of ground layers from 27 paintings and pigments from one of his paintings named "The First Ball".
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INTRODUCTION:
In order to identify the pigments we have examined six painting by Paja Jovanovic from the National Museum Belgrade for which we are certain that they are painted by this artist. First we conducted IR and UV (take away radiography) examinations in order to identify if there are some retouches on these painting. After consultation with restorers we have decided what are the best points on the paintings to be examined with EDXRF. We also did the EDXRF measurements on the back side of the paintings to better identify the ground layers. Here it will be presented the result for painting named "The First Ball" as one example of pigments that Paja Jovanovic used. To analyze the pigments an EDXRF portable system was used working with an X Ray tube tension of 35 kV and a tube current of 0.2 mA; the detector is a SDD (Silicon Drift Detector) with a resolution of 150 eV at 6.4 keV. The analyzed areas have a diameter of 2 mm. In Figure 1 you can see the moment of the EDXRF data collection.
Ground Layers (Priming Coats)
It is very often the case that painters used to buy the material for their paintings from the same supplier or made the ground layers by themselves in the identical manner for some period. In order to see if this is the case for Paja Jovanovic it was examined the ground layers from 27 paintings. For these paintings it is obvious that the canvas was prepared industrially because there is a ground layer all over the canvas, even where there is no painting. The ground layer would be only on the painted surface if painter had applied the ground layer by himself.
The samples were taken from the canvases and immersed in epoxy resin. In order to have the cross sections we grinded the samples mechanically with grinding paper of 500, 800, and 1000. These samples were examined with SEM EDXRF.
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ANALYTICAL RESULTS:
All the points that have been investigated are presented in Figure no.4 on the photograph of the painting and the same numbers are given to the spectra. Summary of the obtained results are given in Table no.1.
The characteristic of all spectra done on the painting "The First Ball" is that there is a pick of titanium zinc. This are also two major signals that can be seen on spectra made on the back side of the painting (Figure no.1).

Figure 1: EDFRF Data collection and spectrum no. 11 of the back side of the painting

On the spectra of pigments where the white colour is used for incarnate (Figure no. 2) the peak of zinc is of the larger intensity. This indicates the use of zinc white ZnO as a white pigment.

Other than zinc, in some places there is evidence of lead white, spectrum no.6, 5 and 2. (Figure no.3). Since lead is visible only on the parts where there is white colour or in mixture with pigments witch are not expected to have lead we can say that this is white lead or 2PbCO3(OH)2.

As the blue pigment on all the spectra there is the peak of iron spectrum no.7 (Figure no.4). This is the sign of the Prussian blue pigment Fe4[Fe(CN)6]3 xH2O. For the green colour in points 4 and 5 and 10 there is the pick of iron also. This is an indication of the earth pigments (Figure no. 3 and 4). Green earth pigments are recognised by the peak of iron, with chromium as a trace element. For the red pigment (Figure no.4) on roses (spectrum no.1) there is the pick for cadmium, cadmium red CdS(Se) and the pick of mercury, cinnabar HgS. The red colour on the books (spectrum 3) in the back shows also red cadmium and the peak of iron (hematite or red ochre also the earth pigment). Cadmium red is pigment that was commercially in use from year 1910 and is always found in some correlation with selenium as the trace element. For the yellow colour on the chair (spectrum no.2) and on the bowl on the table (spectrum 6) there is the peak of iron in combination with chromium which can be assigned to yellow ochre also earth pigments. Summary of the results is given in Table no.1.

Figure 4. Points on the painting show the areas where the EDXRF spectrums are collected and spectras of red, blue, green, yelow pigments

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All of these results are in accordions with results obtained for other paintings of Paja Jovanovic that have been investigated in same manner.
Analytical results for the ground layers are given in Figure no. 5. Ground layers are usually made of calcium carbonate, lead white, zinc white, barium sulphate or their mixture. Titanium white is the white colour that was introduced in painting techniques at the beginning of the XX century. It has been observed that on three paintings there are different kinds of double layers witch are combination of zinc, calcium and lead. There is just one painting with a ground layer made of mixture of zinc white and barium sulphate known as lithopone and just one painting with combination of zinc white and titanium oxide as the ground layer. The former is the case with the painting "The First Ball". There are eight paintings with lead white as the ground layers and the remaining paintings mostly have mixtures of calcium with other white pigments (lead, zinc, lead and zinc together) in 12 cases, and with pure calcium in 5 cases.

Figure 5. Data of ground layers of 27 paintings of Paja Jovanovic made by SEM EDXRF, showing just one with ZnO/TiO2 combination and one with litopone ZnO/BaSO4

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CONCLUSIONS:
Paja Jovanovic was a painter with very good knowledge of painting techniques. His paintings are for almost one hundred years still stable and unchanged. His pallete mostly consists of pigments that are already in wide use at the end of XIX and the beginning of XX centuries. These are cadmium red, red ochre, vermillion for the red colour, Prussian blue for the blue colour, earth green and yellow pigments and different types of white colours as zinc white and lead white.
Since Paja Jovanovic used to travel a lot and change the place of living it seems that he did not have the same supplier for the canvases and probably this is the reason for great diversity of the ground layers found on his paintings. In the painting the "The First Ball" the ground layer is rather unusual and consists of zinc white and titanium white.

ACKNOWLEDGMENTS:
We due many thanks to conservators of National Museum Belgrade, senior conservator Jovan Pantic and Sofija Kajtez, conservator Sanja Pajic for collecting samples and the data. Also we appreciate the technical support given by Goran Bogojevic, Vladimir Radonjic and Bosko Petrovic.

BIBLIOGRAPHY
Z. Antic, Paja Jovanovic, Catalogue of Legate Town Museum Belgrade, Muzej grada Beograda, 1970
N.Kusovac, Paja Jovanovic slike velikog formata, Catalogue, National Museum Belgrade, 1979
C.Seccaroni and P. Moioli, Fluorescenza X, Nardini Editore, 2002
R.Gettens and G.Stout, Painting Materials, D.Van Nostrand Company, 1947
R.V.Grieken and K.Janssens, Cultural Heritage Conservation and Environmental Impact Assessment by Non-Destructive Testing and Micro-Analysis, Balkema Publishers, 2005
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