Pilot study into the effects of solvents on artificially aged egg tempera films

Abstract

Abstract Unlike oil paints, there is virtually no information in the conservation literature on either the ageing of egg yolk tempera paint films or on the effects of organic solvents and other cleaning agents on tempera paint films. The present study is an exploratory investigation of these subjects and focuses on simple observations on reference paint films and analyses of soluble compounds leached by organic solvents. Paint films of vermilion, azurite, lead white, verdigris and films of egg yolk medium alone were subjected to different regimes of accelerated ageing. Accelerated ageing involved light ageing in a xenon arc fadeometer fitted with UV filters, followed by thermal ageing in a humidity controlled oven. Samples of aged and unaged films were treated with a range of simple organic solvents: hexane, acetone, toluene, ethanol and chloroform. Surface topographical changes were monitored by scanning electron microscopy. Compounds extracted by solvent immersion were analysed by gas‐liquid chromatography, as was lipid material remaining in the film.