printing-out paper

Photographic paper coated with silver-chloride emulsions, typically made of gelatin but sometimes of collodion. It was designed for the production of a photographic print from a negative by the action of light alone on light-sensitive material, rather than by development using chemicals. It was in general use, particularly for portraiture, from the 1880s until the late 1920s when developing-out paper became more popular. Because the paper needed to be in contact with the negative until the image was completely visible, a second print could not be started until the first was complete. Photographs made on printing-out paper can have either glossy or matte surfaces and typically have warm image tones.