Megilp

Megilp ( /məˈɡɪlp/) is an oil painting medium consisting of a mixture of mastic varnish and an oil medium: walnut, linseed, safflower, poppy, black oil (linseed oil) cooked with litharge or white lead etc. It makes oil paint thin, glossy, and easy to work, with an extremely short drying time; however, the archival quality is much disputed. Some claim the medium causes paint to become yellow and brittle, while others claim that improperly prepared paint is the cause and that the longevity of Megilp is excellent.