The process of underpainting has such a buttoned-up reputation. If
it were cast in a movie, it would be the uptight, by-the-book stickler
that no one wants to hangout with. That’s because the process of
underpainting is often associated with a belabored, rigid series of
steps that delays us from getting to the “real” painting—which is why a
lot of beginner painters tend to rush it or skip it altogether.
there’s another side to underpainting—one that’s freewheeling with an
“anything goes” attitude. It allows artists to take a dry run at the
canvas, working out compositional questions and value issues or mapping
out a complex color scheme while keeping a lot of options open so that
painting can evolve organically.