The Autochrome, a positive color transparency on glass, was invented by Auguste and Louis Lumière in 1907 and manufactured by them until 1933. Autochromes were made by coating a glass plate with a sticky varnish and dusting it with a layer of randomly distributed, translucent potato-starch grains. These grains, which were dyed red-orange, violet, and green, were then interspersed with fine black carbon dust, and again varnished. The plates were next coated with a light-sensitive gelatin silver-bromide or silver-iodide emulsion. When the plate was inserted into a camera, the light from the lens passed through the dyed starch grains, which acted as color filters before reaching the emulsion. After exposure, the plate was processed to make a unique, full-color, positive silver image.
Alfred Stieglitz learned the Autochrome process while traveling in Europe in 1907 with photographers Frank Eugene, Heinrich Kühn, and Edward Steichen. He made Autochromes from 1907 through 1918, often of friends and family and while he was on vacation at his home in Lake George, New York.