Robert Massey's Canada balsam and sun thickened oil medium recipe resembles closely the legendary but no longer available, olio d'Abezzo. Strasbourg Medium Canada balsam, 4 parts, sun thickened linseed oil, 1 part, turpentine, 2 parts. Combine and warm the ingredients either in hot sunshine or over a double boiler, and stir them until they … [Read more...] about Strasbourg Medium