Underpainting with Earthtones: This was done using green earth and a touch of burnt umber to make a terre vert color similar to what the old masters called "verdaccio," for underpainting tempera. They did full-scale monochrome underpaintings for modeling purposes, and added light glazes of color in many thin layers over top. My manuscript was largely abstract design and had little need of underpainting, but I did some in any case and think it added to the depth of the painting.