Use the medium I purchased (Groves’ 19th Century Copal Varnish) a while ago to match John Fabian Carlson’s (mixed 50/50 with genuine turpentine). Use this medium throughout the painting process. Don’t forget to add linseed oil from layer to layer (fat over lean). Complete the piece as I do and wait 3 months, since last ending with the painting. After waiting until chemically dry, primarily that is the time to mix my glazing medium using Ralph Mayer’s recipe with stand oil. Wait another 3 months and varnish.
