Why Picasso’s yellow paint has faded to brown

Abstract

In Pablo Picasso’s 1907 painting Femme (Époque des “Demoiselles d’Avignon”), a formerly yellow section in the upper left corner is now brownish while another yellow section in the painting has maintained its brilliant lemon hue. According to a new study, this difference is the result of Picasso using two different cadmium sulfide–based yellow paints: they contain different-sized CdS particles and have degraded at different rates (Anal. Chem. 2019, DOI: 10.1021/acs.analchem.8b04914). Daniela Comelli of the Politecnico di Milano and colleagues analyzed paint from the two different sections of the painting, using photoluminescence spectroscopy to look closely at the CdS particles. The emission spectra led the researchers to conclude that the degraded paint contains smaller CdS nanoparticles with more crystal defects, whereas the unfaded paint contains larger CdS grains, which may affect the rate of degradation. The study shows that analyzing the photoluminescence of pigment particles could help art conservators identify the