Black oxide is a conversion coating for ferrous materials, stainless steel, copper and copper based alloys, zinc, powdered metals, and silver solder. It is used to add mild corrosion resistance, for appearance and to minimise light reflection. One of its advantages over other coatings is its minimal buildup. Synthetic Black Iron Oxide is a inorganic pigment of fine particle size and great tinctorial strength, excellent light fastness, resistance to alkali, non-toxic and non-inflammable & produces very attractive shades of variegated colors.