M. Graham & Co's Mars Black oil paint is PBk11 pigment and walnut oil. Lightfast Rating - Excellent Opacity Rating - Opaque Drying Time - Moderate Mars Black is the most opaque black with a neutral tint. Not as black as Ivory Black, it has a firm feeling under the brush and good flow. In the tradition of the masters, M. Graham artists’ oil color is made with pure walnut oil for its brilliance, clarity, texture, and resistance to fading and yellowing. Working in small batches, they craft oil colors true to the roots of Renaissance painting: delicately free-flowing, solvent-free, and with no fillers or additives. With the exceptionally high pigment loads in M. Graham artists’ oil colors, your work will naturally feel more alive and vibrant, imbued with rich, lustrous color for years to come.