Mapping Cadmium-Based Pigments Using Multispectral Imaging Techniques. A Case Study on Mrs. Ševa Ristić by Petar Dobrović

Abstract

AbstractA project of opening the legacy of a famous Serbian painter Petar Dobrović (1890–1942) consisted of a scientific research related to the collection of his paintings, where pigments were analysed using non-destructive imaging techniques. Petar Dobrović was a versatile person, who was engaged in politics, as well as a chronicler of his time, and a proponent of Serbian colourists. His painting is characterized by the intensiveness of colour and strong, impulsive drawing. The painter used a very complex mixture of pigments which resulted, along with the contribution of binder filtering, in a much colourful photograph of UV induced fluorescence that suggests using different yellow pigments; however, the application of green light induced fluorescence in NIR, thus clearly indicating the presence of cadmium pigments in yellow and other paints, and each brush stroke as well. In this paper, we present an application of multispectral imaging techniques complemented with reflectance and fluorescence spectroscopy in order to separate and map cadmium pigments in paints on the painting “Mrs. Ševa Ristić” by P. Dobrović. Multispectral images include reflectance and fluorescence images in a visible and infrared region with filters on 720 nm, 850 nm, and 940 nm. The fluorescence was induced with UV (365 nm LED), blue laser (405 nm), and green (520 nm LED) light. Reflectance (FORS) and fluorescence spectra performed in the selected points in the painting and in several samples of commercial cadmium oil paints verify the presence of cadmium pigments. This application mainly confirms the effectiveness and usefulness of special multispectral fluorescence imaging in NIR domain for locating and mapping cadmium pigments in paints presented in many researches. The excitation with visible green light minimized the contribution of other colours and binders on fluorescence and distinguished different cadmium based pigments.KeywordsCadmiumFluorescenceMultispectral