Old Master Glazing Technique

I finally went back into a drawing I did on masonite and used a very old glazing technique that was used in the 17th century. Well, actually an adaptation of the technique using acrylics. I took this photo using my phone so the image isn't that good but you get a pretty good idea.
What I like about the technique is what happens to the look of a painting. even in a low light the glazes actually glow.