Theophilus

“Take linseed and dry it in a pan, without water, on the fire. Put it in a mortar and pound it to a fine powder; then replacing it in the pan and pouring a little water on it, make it quite hot. Afterwards wrap it in a piece of new linen; place it in a press used for extracting the oil of olives, of walnuts, and express this in the same manner. With this oil grind minium or vermilion, or any other colour you wish, on a stone slab...prepare tints for faces and draperies...distinguishing, according to your fancy, animals, birds, or foliage with their proper colours.”
― Theophilus