s by much the more ancient kind of painting, Till a Flemish painter, John van Eyck, better known by the name of John of Bruges, found out the art of painting in oil, the painters all painted in water and in fresco, both on walls, on wooden boards, and on other materials. When they made use of boards, they usually glued a fine linen cloth over them, to prevent their opening, then laid on a ground of white, and lastly mixed up their colours with water and size, or with water and yolks of eggs, well beaten with the branches of a fig tree, the juice of which thus mixed with the eggs; and with this mixture they painted their pieces.

In limning, all colours are proper enough, excepting the white made of lime, which is only used in fresco. The azure and ultramarine must be mixed with size or gum; but there are always applied two layers of hot size before the size colours are laid on. The colours are all ground in water, each by itself; and, as they are required in working, are diluted with size-water. When the piece is finished, they go over it with the white of an egg well beaten; and then with varnish if required.