GRISAILLE is the name given to the preliminary under painting of the subject of a picture, executed in a monochrome of grey or brown, previous to the application of colour. It is, in effect, a kind of brush drawing in thin oil-paint, usually highly finished, to which the colour scheme is applied. It was commonly used thinly but certain masters used it in impasto afterwards applying the colour in glazes.
It differs from cama'ieu, in which two tints are used.
Its use dates from early times as Zeuxis is said to have employed both grisaille and camaieu but it was not in general use until the 15th century when it was practised by Flemish and Italian masters. It played some part in the development of chiaroscuro, as, with out the aid of colour, the painter had to concentrate on light and shade for his effect.
Correggio is said to have used it extensively and Van Dyck left many small paintings in grisaille which he carried no further. Prud'hon was addicted to the use of grisaille, sometimes substitut ing a light blue tint for the more usual grey or brown, but he more often spoilt his pictures by the use of bitumen. Oudry considered the practice a dangerous one on account of the large amount of white used in it.
In the present day when direct painting is the general practice, grisaille is rarely used.