A variety of black pigment used in printing inks. Black Iron Oxides are commonly natural or synthetic ferrous-ferric oxide (chemical formula FeO-Fe2O3), commonly mined as magnetite, a magnetic iron oxide. Most iron oxides used as black pigments are produced synthetically. Black Iron Oxides are dense, matte blacks which possess high lightfastness and resistance to heat and chemicals (with the exception of acids, which dissolve the pigments). At temperatures above 300oF, however, these pigments turn red. Black Iron Oxides have been typically used in copperplate and die-stamping inks, and magnetic iron oxides are used in inks printed on checks to be read by magnetic ink character recognition (MICR) equipment. Synthetically-produced black iron oxides are bluer in shade than naturally-occurring iron oxides. (See also Black Pigments.)
Also known as Mineral Blacks ('CI Pigment Black 11 No. 77499').