[Karin Wells]

I disagree. In many of the paintings of Sargent that I have seen, he does indeed use an underpainting technique. It is just that he has so darn much "frosting" that it is difficult to see - unless you know what you're looking at.

For this reason Sargent is not really a good one to learn underpainting on. But when you are just starting out is is good to paint something that you like a lot.

Anyhow, Joan, without going any darker or lighter in value on the face, you need to really paint this with more refined detail. The eyes especially need attention and the whole face and figure need to look as if it is carved from marble.

You might use a picture of the original painting without color (xerox, Photoshop print, etc.). But be sure to keep your value range quite narrow at this stage.

"Whites" will appear quite dark, and darks will be much lighter that what you see. See the other thread on "underpainting."