Blockx Artist Oil Colors ivory black 35mL oil paint: Founded in 1865, Blockx Belgian Oil Colors are still handground with slowly rotating stone mills. With the experience of 5 generations of chemists only pure pigment is used for maximum lightfastness, buttery consistency and easy mixing on the canvas itself. Iron oxides, earths and blacks are ground with linseed oil. All other pigments are ground with poppyseed oil which prevents yellowing and dries without wrinkling or mottling. The price of poppyseed oil is 3.6 times the price of linseed oil but it is worth it to avoid the defects of linseed oil with certain pigments i.e. yellowing and producing of an orange skin when drying. We have tested linseed oil vs. poppyseed oil over 144 years and have discovered which oil is best suited for each pigment. Poppy oil is better in most cases, for avoiding wrinkling, but also for consistency, brightness, application, and of course non-yellowing. Blockx does not produce any colors in hues, tones or tints. All fillers, extenders, and driers are excluded. The paint is nothing but pure pigment and oil.