'Messenger Boy' (top)
Museum no. PH.46-1977
'Boys Going to Work' (bottom)
Museum no. PH.44-1977
In 1871, the gelatin dry plate was introduced. This process used a sensitised gelatin emulsion that was dried on the plate and could be stored, protected from light, for months before use. The gelatin process superseded the wet collodion process and revolutionised the world of photography.
In 1873 gelatin-silver bromide papers were invented and first produced by Peter Mawdsley, although they did not come into general use until the 1880s.
They were developing-out rather than printing-out papers, that is, after a brief exposure under a negative, usually in an enlarger, the image was further brought out by chemical development.
Because of the great variety of papers offered by manufacturers, the tones and surface gloss of gelatin prints varied. Generally, however, the tone of the image of the gelatin-silver-bromide print is neutral black. A gelatin-silver-chloride print that has been developed out is blueish or cool in tone, while one that has been printed out is brown or warm in tone. All of these colours can be altered by toning.
The highlights are white unless the underlying paper support has been tinted. Gelatin-silver prints often have a high surface gloss, particularly if they are contact prints. Gordon Baldwin, 'Looking at Photographs', J. Paul Getty Museum, 1991
Both these photographs are gelatin-silver prints, their cool tones suggesting that they are developed-out prints. Note that both prints have a glossy surface, typical of most gelatin-silver prints, but the lower image is more shiny, showing that the gloss can vary in strength between prints.
Although the gelatin print is usually a developing-out process - that is, after a brief exposure to a negative, the print is immersed in chemicals to allow the image to develop - it can also be a printing-out process, similar to the albumen process.
Gelatin, an animal protein, is used as an emulsion to bind light-sensitive silver salts - usually silver bromides or silver chlorides - to a paper or other support. Depending on the type of salts used, silver chloride for printing-out and silver bromide for developing-out, the photograph was placed under the negative under a light until the image appeared in its final form, without chemical development, or exposed under a negative and then immersed in chemicals to allow the image to develop or emerge. The first process, printing-out, was necessarily much longer than for a developed-out photograph.
Photographers from the 1880s and afterward did not normally coat their own papers but obtained them from commercial sources. Gelatin-silver prints had generally displaced albumen prints in popularity by 1895 because they were more stable, did not yellow, and were simpler and quicker to use. Gordon Baldwin, 'Looking at Photographs', J. Paul Getty Museum, 1991
This photograph can be found in Print Room Box 12.