Do you stain all canvases before you beginning painting or only for a portrait and still life? I am curious about the color choice of the stain. I was taught in art school that the white background is essential for the light to bounce back through the color to add vibrancy and life to your colors and painting. So, why the color choice that Mark uses? I'm getting ready to start a 1. landscape and a "don't really know the classification" 2. a close-up of the peeling bark of a paper bark birch tree. I don't know if I want to stain my canvases or not. Is there a previous teaching on this subject?