"As I said earlier, Piero made an intense stydy of painting and perspective. He acquired an intimate knowledge of Euclid, understanting better than any other geometrician the nature of the perfect curves drawn on a basis of regular bodies; and the clearest elucidations of these matters come from his pen. Piero was, by the way, very fond of making clay models which he would drape with wet cloths arranged in innumerable folds, and then use for drawing and similar purposes"