Alkyd artists' paints: Do pigments affect the stability of the resin? A TG and DSC study on fast-drying oil colours

We found that organic and metallorganic pigments interacted the strongest with the alkyd resin, while the inorganic pigments appear to act more as dispersants. The chemical drying of the paint on the other hand, via auto-oxidation, is almost independent of the pigment and only depends on the alkyd content. The paint is fully dried after eight months. Paint samples from two hyper-realistic artworks, “Salto di qualità”, 2003, and “Senza nome”, 2007, by the Italian painter Patrizia Zara were investigated by DSC in order to evaluate the effects of several years of natural ageing on alkyd fast-drying oil colours. At the end of chemical drying, the alkyd colours seemed very stable. Artificial acid ageing visibly damaged the paint replicas, but appeared to act mostly on the pigment rather than on the resin network.