Beginning the underpainting with two yellows. I like to use primaries in layers as I study the subject and the color. Yellow is easiest to start with since it is a the lightest in value. Then red, then blue.
I do an underpainting in pigment dispersions. To find out more about this pigment preparation, go to Guerra Pigments.
When the underpainting is dry, I continue with pastels
with some pastel marks
James, 22"x 17" pastels with pure pigment underpainting, on my sandpaper.