Take a lamp full of linseed oil, and fill the lamp with this oil, and light the lamp. Then put it, so lighted, underneath a good clean baking dish, and have the little flame of the lamp come about to the bottom of the dish, two or three fingers away, and the smoke which comes out of the flame will strike on the bottom of the dish, and condense in a mass. Wait a while; take the baking dish, and with some implement sweep this color, that is, this soot, off on to a paper, or into some dish; and it does not have to be worked up or ground, for it is a very fine color. Refill the lamp with the oil in this way several times, and put it back under the dish; and make as much of it in this way as you need.
Sources:
- Cennini, Cennino, and Daniel V. Thompson. The Craftsman’s handbook. New York: Dover, 1933.