Copal, polymerised linseed oil, turpentine essence. Its composition is very similar to that of the copal paints of the old masters: hard copal resin, cooked linmo oil and turpentine essence. Tougher but softer than soft resin paints diluted with pure essence, it also creates a more resistant film. Very effectively protects the painting against the effects of humidity. It can therefore be used for paintings intended to remain in damp rooms.
Very similar to Copal Lefranc varnish no longer produced.
Copal resin is 30 - 35% in linseed oil and a hint of turpentine.
The thinner is turpentine. No alcohol.