Mars Black, 276 (Liquitex Heavy Body)Mars Black, 276 (59ml Tube) A dense opaque single pigment, with a brown undertone. It is made from mineral iron oxide and is named after the alchemical name for iron: Mars. This is thick, high viscosity, pigment rich professional acrylic color, ideal for impasto and texture. With a high concentration of lightfast artist quality pigment and a satin finish, Heavy Body Acrylic gives you rich, permanent color, with crisp brush strokes and knife marks.