These oil colors offer artists true color for a real value and are intended for painters who are increasing their knowledge of techniques or experimenting with new ideas. Paints are formulated with pure pigments, refined linseed oil and marble dust (calcium carbonate). They are made from approximately half the colored pigments of artist grade oil colors and include added extenders that have good film forming properties that do not muddy color or corrupt texture. Each extender is paired with the pigment so that opaque colors remain reasonably opaque and transparent colors are not clouded.