The word paint is given to any surface coating that both colours and protects a surface. A paint consists of a coloured substance, known as the pigment, and the material that will allow it to stick to the surface, known as the binder. The purpose of the binder is to form a hard, transparent, protective film that holds the pigment to the surface.

Early paints borrowed the same colouring used in food dyes, but they also used ground-up coloured rock. To hold the pigment on to the surface, they used glue-like binders that varied from beeswax to egg white to gum and saps from trees.

The first people to use paint lived in the Stone Age. They ground up coloured rocks to make a coloured powder (the pigment). Then they got sap from trees such as pine trees (the binder) and mixed them together. Then they made their cave paintings using brushes made by crushing the ends of twigs.

Paint-making used the same materials for thousands of years. It was not until the 18th century that linseed oil was found to be a good binder (although it was very slow to evaporate and so the paint stayed sticky for weeks). But the great revolution in paint-making has come about since the early 20th century, and has been due to our knowledge of plastics. Most paint pigments and binders are now made with plastics.