Dammar Oil Varnish and Oil Painting Medium
Dammar (or damar) or soft copal varnishes are soft, very flexible, and transparent but dry slowly. These varnishes have a bright appearance and a faint pale yellow color. The color may be varied from golden yellow to yellowish brown by gamboge, dragon's blood, and asphaltum.
The proportion of the different ingredients varies between:
Ingredient | Parts |
Dammar | 100 |
Boiled linseed oil | 50 to 120 |
Spirits of gum turpentine | 200 to 500 |
The dammar is pulverized and dissolved in spirits of turpentine, and boiled linseed oil or linseed oil to which a liquid drier has been added is run into the solution.
If the harder kinds of dammar are used, they may be more soluble in linseed oil by adding a small quantity of soft dammar.
Reference
Based on the text from John Geddes McIntosh, The Manufacture of Varnishes and Kindred Industries, Based on and Including the "Drying Oils and Varnishes" of Ach. Livache, Vol. 2, Greenwood & Son, 1908, p. 163