Classic comic artist Roy Crane (1901-1977) reminds us of the compositional importance of black.
“Get all you can,” he said in his famous scrapbook. “But use it mainly to bring out the color of white.”
Applies to painting, too. (Rembrandt, Descent from the Cross)
Wikipedia on Roy Crane
More pages from the scrapbook at the blog "Hairy Green Eyeball."
Books: Captain Easy, Soldier of Fortune: The Complete Sunday Newspaper Strips 1933-1935 (Vol. 1) (Roy Crane's Captain Easy)