Grisaille is the Monochrome painting, generally employing shades of gray (the term derives from gris, the French word for "gray". Painting technique by which an image is executed entirely in shades of gray and usually modeled to produce the illusion of sculpture or relief. It was used especially by 15th-century Flemish painters (e.g., Jan van Eyck's Ghent Altarpiece, 1432) and in the late 18th century to imitate Classical sculpture in wall and ceiling decoration.