When an opake body is situated between the eye and the luminary, so that the central line of the one passes also through the centre of the other, that object will be entirely deprived of light.
Chap. CCIX.—Of proper Back-grounds for Figures.
As we find by experience, that all bodies are surrounded by lights and shadows, I would have the painter to accommodate that part which is enlightened, so as to terminate upon something dark; and to manage the dark parts so that they may terminate on a light ground. This will be of great assistance in detaching and bringing out his figures[1].
Chap. CCX.—Of Back-grounds.
To give a great effect to figures, you must oppose to a light one a dark ground, and to a dark figure a light ground, contrasting white with black, and black with white. In general, all contraries give a particular force and brilliancy of effect by their opposition[2].
