ANALYSIS AND TREATMENT OF A PAINTING BY KEES VAN DONGEN: FTIR AND ELISA AS COMPLEMENTARY TECHNIQUES IN THE ANALYSIS OF ART MATERIALS

Recent examination and treatment of the Worcester ArtMuseum’s Reclining Nude, c. 1925, oil on canvas, by theDutch-born Fauve artist Kees Van Dongen (1877-1968) indicatethat the artist used unorthodox materials and techniques,including selective varnishing to adjust color saturationand surface sheen. Examination also revealed resinlikebeads exuded from unvarnished passages of paint consideredartist-applied retouches. ATR-FTIR micro-spectroscopyof the exudate suggests the presence of gum arabicand sucrose, two common components in watercolorformulations. In order to verify the presence of gum arabicin the exudate, a newly developed ELISA protocol wasused, which confirmed the presence of gum arabic. Thismay indicate that the artist modified his oil paint withgouache or watercolor, ultimately resulting in phase separationand subsequent beading up of water-soluble componentsfrom within the paint’s predominantly oil component.The identification of water-soluble materials within an otherwisenon-water-soluble paint surface proved critical informulating an appropriate cleaning approach. Although theexact cause of the exudate is debatable, it ser ves as a cautionarynote for conservators faced with the challenge oftreating paintings by Van Dongen.