Working on a seated figure, half-length, north light from a tall window. Left forearm sits in that narrow band of light before it falls into the shadow of the drapery, and I spent two hours yesterday getting the transition right. The drawing underneath is still visible there, a few dark strokes I never covered. Normally I'd paint them out without thinking. This time I stopped.

Part of me says leave them. They describe the form better than the finished passages do, they're honest about how the thing was made. The other part says I'm just dressing up an unfinished arm as a decision.

I know the answer is supposed to be "it depends," but I don't want that. I want to know what you do when a mark that was never meant to survive turns out to be the best thing in the corner. Do you trust it and build around it, or do you cover it because the rest of the painting isn't built to carry it?