Term used to describe the technique of producing an image by the action of light on a chemically prepared material. Although used privately as early as 1833, it was not until the public discussion of the first processes in 1839 that the term popularly attributed to John Herschel came to be used in its present general sense.
See also Conservation for photographs
J. P. Ward, revised by Gerald W. R. Ward
The process for producing these was introduced by Louis-Désiré Blanquart-Evrard in 1851. It soon became the most widely used means of producing photographic prints in the 19th century, until c. 1895 (e.g. Devil’s Canyon, Geysers, Looking Down by Carleton E. Watkins, 1868–70). Paper was coated with salted albumen derived from egg white and sensitized with silver nitrate before use. The print was made by placing this sensitized paper in a printing frame beneath a negative and exposing it to daylight until an image appeared. When fixed, the image was a red-brown colour with yellow highlights. From the mid-1860s lightly tinted albumen paper became popular as a means of masking or disguising the yellow highlights, which many photographers found objectionable. Most albumen prints were gold toned to the rich purple-brown image colour often described as ...