Grisaille (/ɡrᵻˈzaɪ/ or /ɡrᵻˈzeɪl/; French: gris [ɡʁizaj] 'grey') is a term for a painting executed entirely in shades of grey or of another neutral greyish colour. It is particularly used in large decorative schemes in imitation of sculpture. Many grisailles in fact include a slightly wider colour range, like the Andrea del Sarto fresco illustrated. Paintings executed in brown are referred to as brunaille, and paintings executed in green are called verdaille.
A grisaille may be executed for its own sake, as underpainting for an oil painting (in preparation for glazing layers of colour over it), or as a model for an engraver to work from. "Rubens and his school sometimes use monochrome techniques in sketching compositions for engravers." Full colouring of a subject makes many more demands of an artist, and working in grisaille was often chosen as being quicker and cheaper, although the effect was sometimes deliberately chosen for aesthetic reasons. Grisaille paintings resemble the drawings, normally in monochrome, that artists from the Renaissance on were trained to produce; like drawings they can also betray the hand of a less talented assistant more easily than a fully coloured painting.