When do you set aside a painting--decide it is not worth pursuing at least in its current form? (Ignoring inner voices which proclaim "finish what you start" or "don't give up...")
That question came up this morning when my friend Mark paid a studio visit. He said that he will abandon a painting when he feels that it is not leading him into new territory. I liked that...the idea of the painting pulling you along. When you are pulling it, often it is towards the tried and true, and that robs you both of energy and vitality.
There are also times for me when I'm too intent on expressing something that is indeed a new idea, but one that has formed in my mind, as opposed to having evolved naturally out of the process. It seems better in both cases to back off and start again. Or paint over or wash out...anything to steer clear of that insidious energy drain of trying to force a painting to work.