But the following mediums of at least partially known ingredients are on the market. Creative Mark produces a copal resin painting medium. Lefranc and Bourgeois Apparently a form of drying medium used by academic painters of the late 19th century invented by a Mr. Durozier of France. Critics say that the original siccatif de Haarlem and siccatif de Courtrai both contain ingredients that turn dark, brittle and crack. Perfect for brilliant and precise detail work.
Finished paintings have a luminescent, glossy appearance.
First re-created by Jacques Maroger the head curator of the Louvre in the 1930's. Made by combining oxidized linseed oil and mastic varnish resin to create a gel-paste. When mixed into colors they become richer and deeper and remains lustrous even when dry. An emotional debate rages as to whether or not the use of a boiled oil is archival in painting mediums. Many claim that the lead dryer never ceases to oxidize the paint film, endangering its permanence and long-term flexibility.