Abstract painting, particularly the type without any imagery, causes one to wonder how the artist knows the picture is finished. The short answer is a quote from Picasso (or at least a paraphrase), which is something to the effect that "a work of art is never finished, it is simply abandoned."
The word "abandoned" is a bit harsh, as it has a negative connotation, but it is close. Obviously, it is not possible to say that a painting with no imagery, or imagery that is a loose representation of a thing, is ever "finshed." I can say your portrait is finished. I can say the painting of an apple is finished. But how can I say that a painting that consists of only a series of lines, circles and masses of color is finished?
When I start to paint I generally have no plan at all. At best, I may have a vague notion of what I hope to achieve, but there are no plans or sketches. I allow the painting to sort of take its own path. I put on some black, swish it around and see what happens. I add some white, and maybe some color, and see where these things take me.
There comes a time when I wonder if there is anything else I can or should do. One can over work a picture. Just as a lawyer needs to know when to shut up, the artist needs to know when to leave the picture alone. This point in development of the painting is not always clear. There often comes a point when I look at the painting and don't know what to do next. That is a good time to stop, at least for a while. I then put the painting to the side for maybe several weeks, and look at it later.
At that point, one of three things will happen. 1) I like it the way it is and decide to quit; 2) I don't like it, and I see what else might be done to it; or 3) I paint over some or all of it. This may go on for several rounds. I continue with the "unfinished" picture until I like the way it looks, or I give up and paint over it.
In the end, there should be some feeling of satisfaction I get from looking at it, at which time I try not to ruin it putting more paint on it.
Visit my website at www.MichaelHendersonGallery.com