On occasion I have been asked to paint a painting as a commission, perhaps the same as another painting of mine that has been seen and liked. As much as I would like to accept, I always refuse. I try to explain that it is impossible to duplicate a painting, that no one painting is ever the same as another. However, this is a difficult concept for people to understand and I think they often wonder why I won't do it.
Recently I was delighted to read James Elkins writing about this individuality of every brushstroke in every painting:
"...each painting would insist on its own uniqueness, because no mark can be like any other, and no picture can duplicate another.... A painting or drawing...is unique, and so is every mark on it. As every artist knows, a single brushmark can never be retrieved: if it is painted over, it is gone, and no matter how many times the same hand passes over the same inch of canvas, the mark can never be reproduced. Every mark is a different beginning ...." P. 41, "What Painting Is" by James Elkins.
If every brushstroke is unique, you can imagine how a whole bunch of brushstrokes can never add up to the same painting.