This is employed by the artist as a vehicle to use with some of his colors. It is composed of either poppy, nut, or linseed oil, to which a drying quality has been given by soaking in it for some days the acetate of lead, in the proportion of one ounce to the pint of oil. This being poured off clear, is mixed, according to the judgment of the artist, with strong mastic varnish. It has much body, works easily, and dries rapidly. It may be diluted in use with spirits of turpentine.