Hardness dammar

A varnish is often appHed on top of the paint layers. A varnish serves two purposes as a protective coating and also for an optical effect that enriches the colors of the painting. A traditional varnish consists of a natural plant resin dissolved or fused in a Hquid for appHcation to the surface (see Resins, natural). There are two types of varnish resins hard ones, the most important of which is copal, and soft ones, notably dammar and mastic. The hard resins are fossil, and to convert these to a fluid state, they are fused in oil at high temperature. The soft resins dissolve in organic solvents, eg, turpentine. The natural resin varnishes discolor over time and also become less soluble, making removal in case of failure more difficult (see Paint and FINNISH removers). Thus the use of more stable synthetic resins, such as certain methacrylates and cycHc ketone resins, has become quite common, especially in conservation practice. 

Dammar resin [dam(in)ar]. Pale yellow, transparent drop-like or irregularly shaped pieces of resin with a we ly aromatic odor from the south east Asian pitch tree (Shorea wiesneri, Dipterocarpaceae) and other Shorea or Hopea species. D. has varying hardnesses depending on its origin. 

Feller, R. L. (1958). Dammar and mastic varnishes hardness, brittleness, and change in weight... 

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