Introduced in 1907 by the brothers Auguste and Louis Lumi?re, Autochromes were one of the earliest commercial ?full-colour? photographic processes. Colour is created by dyed red, green and blue potato starch grains, roughly 1.6 million grains to the square centimetre, embedded in gelatin silver emulsion. When exposed in the camera they acted as filters, allowing light to pass to the emulsion base. The autochrome was then processed as a one-off positive transparency. When held to the light the original scene was recreated in colour as light passed through coloured starch grains.