Combined Macro-XRF and X-ray radiography analysis of Renaissance masterpieces

Macro-X-ray fluorescence (MA-XRF) and X-ray radiography (XRR) are complementary, nondestructive techniques extensively utilized in the analysis of paintings. Macro-XRF employs focused beams measuring a few hundred microns (generated through polycapillary optics) to produce highresolution elemental images by scanning the entire painted surface and collecting the fluorescence signals emitted by the atomic species composing the pictorial materials. Conversely, XRR generates images based on the differential absorption of X-rays by materials with varying densities, uncovering hidden structures, compositions, and layers invisible to the naked eye. The integration of Macro-XRF and Digital X-ray radiography provides conservators, art historians and researchers with a deeper and more comprehensive understanding of the original material composition, artist's modus operandi, structural details, creative processes and historical context. Recently, the Macro-XRF scanning system and the new XRR platform developed at the XRAYLab of CNR-ISPC (Catania) were employed to conduct a study focused on panel paintings by Renaissance masters. The results that we will present in this work have enhanced our understanding of both the material composition and painting techniques, while also contributing to the reconstruction of the history of these iconic works of art.