Venice turpentine varnish

The terpenoid resins commonly used as artists materials were colophony, Venice turpentine, mastic, dammar, copals and sandarac, and most of the scientific literature concerning the identification of Old Master varnishes and the study of their degradation focuses on these resins. 

Another varnish may be made by using gum shellac, oneounoe gum sandarac> one ovxxxce Venice turpentine, onedrachm and ninety-eight per cent, alc ol, one gallon. 

Venice turpentine has been used in picture varnishes and as a tackifying resin in adhesives partly because it inaeases the flexibility of the film, though this effect will diminish as the monoterpenes evaporate. Canada balsam was widely used for mounting specimens on microscope shdes and as a glass adhesive, though again the evaporation leads to shrinkage and distortion. 

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