Multi-analytical non-invasive study of modern yellow paints from postwar Italian paintings from the International Gallery of Modern Art Ca Pesaro, Venice

We present a multi-analytical non-invasive approach for the characterisation of yellow paints used in three paintings from the International Gallery of Modern Art Cà Pesaro, Venice. The paintings selected for this study were executed in oil-based media between 1940 and 1960, they are unvarnished and have large monochromatic yellow areas. We focus on the identification of yellow pigments with a combined approach based on non-invasive portable X-ray Fluorescence spectrometry, complemented with VIS reflectance, remote-Fourier Transform Infrared and Raman spectroscopies. Different yellow pigments including Chrome yellow Naples Yellow and Cadmium-based yellow were identified. Their identification is of fundamental importance because several modern inorganic yellow pigments (in particular chrome and cadmium-based pigments) are known to exhibit peculiar degradation patterns, leading to noteworthy aesthetic changes in paint such as darkening and fading. This work highlights the suitability of non-destructive techniques for the characterisation of modern paints and the utility of an integrated approach to obtain useful information for preventive conservation. Results demonstrate the need to complement elemental data acquired using portable X-ray Fluorescence with suitable complementary molecular spectroscopic techniques.