Although I haven't copied old masters works for quite some time, I did this one in order to test an amber varnish that I made. It is many layers thick, employing amber in each successive layer. I am sold on hard resins in painting mediums. The luminous qualities are, in my opinion, much different than when using modern resins. The amber I used in this one was from the Baltic region, and was obtained from Kremer. It was made by heat fusing the resin, or in effect running it. It was then combined with linseed oil, under high heat, and then cooked into more oil to make a medium. This was added in small quatities to the oil paint, in gradually increased amounts, with each layer. The light enters the surface, and as it is returns back out after striking gradually built up under layers, it creates a luminous effect that causes it to appear to glow from within.