The word Macchia, literally a blot, is generally used by Italian writers, by Vasari for instance, for the local colour. Boschini understands by it the relative depth of tones rather than the mere difference of hue. "By macchia," he says, "I understand that treatment by which the figures are distinguished from each other by different tones lighter or darker."—La Carta del Navegar, p. 328. Elsewhere, "Colouring (as practised by the Venetians) comprehends both the macchia and drawing;" (p. 300) that is, comprehends the gradations of light and dark in objects, and the parts of objects, and consequently, their essential form. "The macchia," he adds, "is the effect of practice, and is dictated by the knowledge of what is requisite for effect."