CathayCoat™ BB31 Black Iron Oxide strikes that coveted balance between price and performance. This pigment does not go through the extensive processing of our “Best Series” pigments, but it still provides the quality needed for many applications. Like all Black Iron Oxides, BB31, has excellent lightfastness and chemical resistance. In normal applications it is considered a permanent pigment. While weaker than typical Carbon Black pigments, Black Iron Oxides are more compatible with water base systems. Black Iron Oxides also have the unique property of being magnetic, since they are based on the mineral Magnetite.