Libro dell’ Arte – Cennino Cennini (beginning of the 15th century)
How to make various sorts of black. Chapter XXXVII
Know that there are several kinds of black colors. There is a black which is a soft black stone; it is a fat color. Bearing in mind that every lean color is better than the fat one (except that, for gilding, the fatter bole or terre-verte which you get for gilding on panel, the better the gold comes out) let us leave this section. Then there is a black which is made from vine twigs; these twigs are to be burned; and when they are burnt, throw water on them, and quench them; and then work them up like the other black. And this is a color both black and lean; and it is one of the perfect colors which we employ; and it is the whole. ….. There is another black which is made from burnt almond shells or peach stones, and this is a perfect black, and fine. There is another black which is made in this manner: take a lamp full of linseed 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.