Artificial light ageing of triterpenoid varnishes by means of a weatherometer is found to simulate the oxidation processes that occur on paintings, only when irradiation by UV light is excluded. In the presence of UV light a specific type of A-ring oxidation takes place. This latter oxidation process has not been observed in aged varnishes from paintings.

CNRS Éditions
J. Goupy , J. -P. Mohen

van der Doelen, G. A, van den Berg, K.-J, & Boon, J. J. (2000). A comparison of weatherometer aged dammar varnishes and aged varnishes from paintings. In J Goupy & J. -P Mohen (Eds.), Art et Chimie, la Couleur: Actes du congrès (pp. 146–149). CNRS Éditions.