The concept of (POP) Printing-Out Paper originated in the lab of Johann Heinrich Shultze (1687-1744) in 1725-1727, when he observed the darkening action of light on a liquid mixture of silver chloride and chalk. The light-sensitive quality of silver chloride was the result of sodium chloride in combination with an excess of silver nitrate. Shultze applied this sensitized mixture to white leather and printed-out “photograms” using stencils as his subjects. It is important to again note that in 1834, William Henry Fox Talbot, who is responsible for the first negative to positive photographic print, was making his Sciagraphs / Photogenic Drawings with sodium chloride salted papers with excessive amounts of silver nitrate (silver chloride) just as Shultze had done. Fox Talbot, however, had the advantage of knowing about Herschel’s 1819 discovery of the fixing attributes of hyposulfite of soda which allowed him to preserve his images.

In the late 1860s silver chloride / gelatin-based printing-out papers were commercially introduced to the public by Johann Baptist Obernetter. As had been the case with albumen’s rise to popularity over less convenient imaging systems, POP papers were far easier to use and they ultimately replaced the commercially produced albumen papers in the marketplace.

POP paper is commercially distributed today by the Chicago Albumen Works and comes boxed and ready to use. A negative is placed in a contact printing frame along with the POP paper and exposed to UV light until the image “prints out” the way the artist wants it to look upon completion. The exposed print then washed in distilled water and toned, fixed in a sodium thiosulfate solution, and washed for permanence.