The old adage to let sleeping dogs lie takes its sense from the fact that a dog awake is often territorial and typically barks or even growls and sometimes bites. To let sleeping dogs lie means that you leave undisturbed a matter that, if raised, could easily lead to argument or division.
But I can imagine how in the long rich artistic past this saying might easily have taken a different meaning, for among artists the thing you do upon encountering a sleeping dog is that you quietly and quickly pick up your notebook, grab a pencil, and start drawing. Naturally you don’t want to wake him up — not unless you draw very rapidly and have a talent for capturing the trace of things that move.
Our dog Spottie was a study in blacks. He had the most richly deep satin black coat of any animal I’ve ever seen. He was so much dog, too, that I’m not surprised at finding that I left the drawing unfinished. He was a very big dog. He seemed to go on forever. Clifford the Big Red Dog had nothin’ on Spottie, not for size, not for color, not even for adventure.
Anyway, here’s the advice for artists: let sleeping dogs lie, and then draw them!