Has anyone experienced intentionally letting an under painting or initial sketch dry as Michael Klein in the second portrait session of the free live-stream, and then coating the entire painting with a layer of retouch varnish, before painting the second paint layer into the varnish?
I never saw this before. I have seen and oiled out a painting with linseed or walnut oil after it dried, but I have never painted into retouch varnish. What are the advantages of this? His only explanation on the live stream was that this was the way he did it, his process. What are the advantages?