IDENTIFYING PIGMENTS A Multi-Instrumental Study of Ivar Arosenius’ Use of Pigments

Abstract: In this study, the pigments used by the Swedish artist Ivar Arosenius (1878-1909), in one of his sketch books (T 19/2001, Gothenburg Museum of Art), were examined and identified. The study used noninvasive and non-destructive analytical methods, and aims to determine what pigments Arosenius used and how well the analytical methods perform in examination of this particular object. The basis for this study is the lack of knowledge about the use of materials by Arosenius. A three-year research project, called the Arosenius Project, is currently gathering information about the artist, aiming to digitize and make it more accessible for researchers and for the public. The project is based in Gothenburg and Stockholm and is funded by The Royal Swedish Academy of Letters, History and Antiquities and Riksbankens Jubileumsfond. The results of this study will contribute information to the project and to the general understanding of Arosenius’ artistry. Examination was conducted using optical microscopy, X-ray fluorescence (XRF), ultraviolet-visible fiber optic reflectance spectroscopy (UV-VIS FORS), and multispectral imaging (MSI). The methods provided information about the color, chemical composition, and reflectance spectra of the pigments, as well as their properties in various spectral ranges. A probable identification is presented for 27 of 31 pigment samples in the sketch book. 15 different pigments have been identified, vermillion being the most frequently used. The study shows that the analytical methods are useful for pigment identification, but examination of objects of art is complex due to small areas of analysis, mixed and/or layered pigments, and to the consideration of the safety of the object.