The underpainting is painted in 9 values of burnt sienna and lead white. In the underpainting, everything will be painted lighter than its true value. I find that the colors look richer with a paler ground beneath them.
Generally, I try to blend out all brush stroke marks in the underpainting, so that a random stroke won’t show through and interfere with the finished painting. In this case, because the bricks are very rough, a little texture in the underpainting will contribute to the impression of roughness, so I don’t blend out the strokes.
Things are kept very simple in the underpainting. I don’t need to show any details. It would be a waste of time, since this will all be painted over. The real painting doesn’t happen until I start the overpainting!
I try to keep the edges sharp, because I don’t want to lose the drawing. Edges will be softened in subsequent layers of paint. I also keep the paint layer very thin so that it won’t take long to dry. It has to be completely dry before I can start the over-painting.
I work from left to right so that my hand doesn’t smear my completed work.
On the basket, I painted in the lines more sharply than they really appeared so that they could guide me when I start to paint. The paperweight is more loosely painted. I just need the major landmarks indicated at this point.
Above is the finished underpainting. I’ll let it dry for at least a week before I start to paint.