Paint is any liquid, liquefiable, or mastic composition which, after application to a substrate in a thin layer, is converted to a solid film. It is most commonly used to protect, color or provide texture to objects.
In 2011, South African archeologists reported finding a 100,000 year old human-made ochre-based mixture which could have been used like paint. Cave paintings drawn with red or yellow ochre, hematite, manganese oxide, and charcoal may have been made by early Homo sapiens as long as 40,000 years ago.
Ancient colored walls at Dendera, Egypt, which were exposed for years to the elements, still possess their brilliant color, as vivid as when they were painted about 2,000 years ago. The Egyptians mixed their colors with a gummy substance, and applied them separate from each other without any blending or mixture. They appeared to have used six colors: white, black, blue, red, yellow, and green. They first covered the area entirely with white then traced the design in black, leaving out the lights of the ground color. They used minium for red, and generally of a dark tinge.
Pliny mentions some painted ceilings in his day in the town of Ardea, which had been done prior to the foundation of Rome. He expresses great surprise and admiration at their freshness, after the lapse of so many centuries.
Paint was made with the yolk of eggs and therefore, the substance would harden and adhere to the surface it is applied to. Pigment was made from plants, sand, and different soils. Most paints used either oil or water as a base.
A still extant example of 17th century house oil painting is Ham House in Surrey, England, where a primer was used along with several undercoats and an elaborate decorative overcoat; the pigment and oil mixture would have been pounded into a paste with a mortar and pestle. The process was done by hand by the painter and exposed them to lead poisoning due to the white-lead powder.
In 1718, Marshall Smith invented a “Machine or Engine for the Grinding of Colours” in England. Although we don’t know precisely how it operated, it was a device that increased the efficiency of pigment grinding dramatically.