A transparent brownish-black. One of the most popular colors of the 18th century, most Paintings made with liberal use of genuine Asphaltum (a semi-solid organic material found with oil deposits) have fallen apart. The color Asphaltum is worth saving, so Robert Gamblin formulated this Asphaltum to match the original in color only. Gamblin Asphaltum is lightfast and permanent. Pigment: Transparent Mars Red, Bone Black (PR 101, PBk 9), Vehicle: Alkali refined linseed oil Lightfastness I, TRANSPARENT.