Here's a sketch I did at a recent life drawing group:
I've been doing a lot of Repainting lately, while realizing this can often be unwise. It's tempting to take a painting that is partially successful and see if it can be improved upon. Many artists find this quite useful and the built up layers can add interesting depth and texture. Recently I came across a website devoted to Mabel Alvarez who did this later on in her artistic career using her newer vision of art:
She was admonished for this practice in a 1960 letter to her from Earl Rowland of the Pioneer Museum & Haggin Galleries in Stockton, California. “Now I have a few things to say that might be interesting to you. You greatly shocked me when you said you are painting over some of your old canvases and doing things in your new style on top of them. This worries me. Such a practice could only arise from two causes. One, that you fail to appreciate your older work sufficiently and two, that the purchase of materials is a problem with you which I think is not likely to be the case.” Alvarez Papers AAA.