[Marta Prime]

I do the entire underpainting using nothing but black, white, and an alkyd resin medium, keeping it very thin. I work out the entire composition and all the values this way, ranging from very light to fairly dark.

I've tried using asphaltum, and umbers, but I just don't care for them. I know I've read that the painting is much warmer if you use browns, but I still like working with the greys. It looks like a finished black and white painting before I start layering in transparent colors.