Oil used to make oil paints comes from several sources; the most common used is linseed oil, made by boiling the seed of the flax plant. The oil is then mixed with pigments to attain color. Common pigment bases include lead bases and cadmium bases. In recent times, synthetic pigments have become popular; however many are not tested well for their lightfastness.

Notes for usage of oil paints

1. Many oil paints contain toxic chemicals. Lead is known to cause cancer with prolonged exposure and cadmium can cause cancer with prolonged inhalation.
2. Wash your hands well and avoid unventilated rooms when painting.
3. Paper or rags soaked in pure linseed oil are known to spontaneously ignite. Be sure to soak the rag in water or seal it in a bag of water or metal can.
4. Although synthetic pigments are popular, there are no good synthetic pigments to replace the cadmium colors.
5. As with all oils, linseed oil is highly resistant to water and requires some sort of paint thinner (soap, turpentine, benzene-based thinners) to clean up.
6. It is no longer possible to buy true lead white oil paint. Flake White is made from white lead, however it is mixed with safflower oil which is slower drying than linseed oil.

See also oil painting