Eight portraits at the Tate Gallery by Sir Joshua Reynolds (1723-1792) were examined to assess whether the varnishes could be removed safely. Analysis of the paint medium was carried out with DTMS (direct temperature-resolved pyrolysis mass spectrometry), varnish having been removed beforehand in test cleans by a variety of methods. Most samples included mixtures of the following media: linseed and walnut oils (some with lead driers), beeswax, mastic resin, Venice turpentine and on occasion bitumen. Beeswax was a significant component of the paint film in several paintings. An assessment was made of the effects of cleaning methods on areas of paint.

James

Jones, R. R, Townsend, J. H, & Boon, J. J. (1999). A technical assessment of eight portraits by Reynolds being considered for conservation treatment. In 12th Triennial Meeting Lyon 29 August - 3 September 1999 ; Vol. 1, ICOM-CC ICOM Committee for Conservation (pp. 375–380). James.