EN
From 2004 until 2000 in the Painting Conservation Study of the Royal Castle in Warsaw, the conservation of two tronie portraits The Scholar at the Lectern and The Girl in a Picture Frame, which are ascribed to Rembrandt and signed bv his name, date of creation: 1641, was performed. The paintings, which had belonged to the Lanckororiscy Family, were gifted to the Royal Castle in Warsaw in 1994 by Karolina Lanckororiska, together with other historic assets from her family collection. Before then, both works had been regarded as lost since World War II. This gave rise to doubts concerning their attribution, particularly with regard to the portrait of the woman. As a result, it was decided that comprehensive research work should be undertaken. The conservation works involved, among others, analyses of the paint layers and priming paints of both paintings, the results of which are discussed iti this publication. The analyses of the pigments and fillers, stratigraphie sections of samples, microscopic photographs and the interpretation of SEM-EDS spectrums were performed by mgr Anna Nowicka (Faculty of Conservation and Restoration of Works of Art of the Academy of Fine Arts in Warsaw), the instrumental examinations of binders were performed by dr Irmina Zadrożna (Faculty of Conservation and Restoration of Works of Art of the Academy of Fine Arts in Warsaw, the Faculty of Chemistry of the Warsaw University of Technology), while the SEM- -FDS (scanning electron microscopy with energy' dispersive system) tests were performed by mgr Marek Wróbel (Institute of Hydrogeology and Engineering Geology of tht‘ Warsaw University). The analysis of the binders was carried out using the gas chromatography-mass spectrometry (GC-MS) method, with the Fourier Transform Infrared Spectroscopy (FI 1R) analysis as a supplementary technology. Flit" main difficulty connected with the interpretation of the results obtained was the fact that faces in both paintings, but especially in the portrait of the woman, had been covered with numerous repaints dating back to the 18th and 19th centuries, or even, perhaps, to the 17th century. On the basis of th«; tests, it was discovered that the board on which The Scholar at the Lectern was created had been covered with a thin layer of priming paint, which contained a preponderance of white lead and a tiny amount of calcium carbonate. The binder of the priming ground was gluten glue to which nut oil had been added. A layer of weak yellow- brown imprimitura was applied onto the priming paint. The following pigments were found in the painting: white lead, lead-tin yellow, ferrite yellow, smalt, green earth, malachite, boneblack, bituminous bronze, iron oxide red, organic red, and chalk. The binder of the paint layers was nut oil. The painting The Girl in a Picture Frume was painted on the priming paint, applied in two layers; the first thicker layer contained chalk as a filler, whereas the second, thinner layer consisted mainly of white lead, with a tiny amount of chalk. In both layers, an emulsion binder, prepared on the basis of gluten glue and an unidentified oil, was used. The layer containing white lead is fatter. The painting was painted using the following pigments: white lead, ferrite yellow, green earth, boneblack, bituminous bronze, vermilion or cinnabar of natural origin, organic red, and chalk. The presence of nut oil and linseed oil was found. No remaining traces of the original varnish was found on faces of either painting. I ht; aforementioned analyses helped to obtain important information that, iu combination with the results of research work carried out by art historians and conservators, led to the formulation of the final conclusions confirming Rembrandt’s authorship in the case of both portraits.