Early Degradation Behavior of Amber-Based Paint Layers in The Temptation of St Anthony by Salvador Dalí

The iconic Dali’s painting The Temptation of St. Anthony dated 1946, housed in the Royal Museums of Fine Arts of Belgium since 1965, displays worrying surface conditions in specific areas, notably the figure of St. Anthony. The problematic paint layers similarly exhibit uneven transparency and a rugged surface irrespective of their color, raising questions about whether these features reflect deliberate artistic intent or material degradation. To evidence potential degradation mechanisms and to identify the associated painting materials, Dali’s picture has been investigated through a large panel of imaging and analytical techniques, including digital microscopy, MA-XRF, Raman and FT-IR spectroscopies, XRD and Py-GC–MS. The obtained results were subsequently assessed against the material and technical information collected from Dali’s 50 Secrets of Magic Craftsmanship, as well as against archival photographs. By combining historical and multi-analytical approaches, it was possible to diagnose the altered condition of the artwork, but above all to determine when and how the deterioration patterns took place. Visible changes of appearance occurred prior to 1965 and were most probably already initiated during the curing and drying processes of the paint films. The present study tends to demonstrate the key roles of mobile resin acids from amber, reactive zinc oxide pigment suspected of containing crystal defects, uncured lead-white-rich underlayers, and chlorine environmental contamination, regarding the early and peculiar degradation behavior observed on Dali’s masterpiece.