Italian term. Mordant composed of a varnish and a cooked drying oil that may be used to substitute the bole in gilding with gold leaf. It is particularly noted when one must add gold onto a finished painting, as in the case of highlights, and for these highlights burnishing is not required. Giorgio Vasari (1568) notes that this mordant is adapt for a wide variety of surfaces (stone, wood, canvas, metal, etc.) stating that: "it is made of various sorts of drying pigments and of oil boiled with the varnish in it. It is laid upon the wood which has first received two coats of size. And after the mordant is so applied, not when it is fresh, but half dry, the gold leaf is laid upon it."