Abstract
Acrylic polymer dispersions, regularly used as artists' media or varnishes, were monitored for the development of yellow discoloration under natural aging conditions for a period of two years. Films of a number of water-based acrylic artists' media were kept under visible light of either moderate (150 lux) or low (50 lux) intensity (cycled on 10 hours per day) and were compared to films kept in dark storage, which have been observed to yellow. Results after two years show that exposure to visible light at 150 lux effectively prevented film discoloration in a number of products, and seemed at least to slow the rate of yellowing in others. Exposure to low-intensity (50 lux) lighting was found to be less effective in preventing this yellowing.