An early commercial colour photography process, introduced by the Lumière brothers in 1907, which applied the principles of additive colour synthesis. Autochrome used a glass plate coated with a mosaic of dyed potato starch grains (red-orange, green, and blue-violet) over a black-and-white photographic emulsion. When exposed to light and viewed, the plate produced full-colour images with a soft, painterly effect. Autochrome was one of the first widely available methods for producing natural-looking colour photographs and remained popular until the 1930s.