Most photographic prints made before 1855 are salted paper prints. They were printed using paper negatives from the calotype process, published in 1841 and its developments such as the waxed paper process, and from the wet plate (collodion) process announced in 1851.
After 1855, photographers increasingly turned to albumen prints, either matt albumen or gloss, generally using factory coated albumen papers made using Rives or Saxe papers. Albumen prints are the most common type of photograph from 1865-95, when they were superseded by emulsion based (gelatin or collodion) papers.
Salted paper enjoyed a minor revival among artistic photographers around 1880-1910, both using materials coated by the photographer and a number of factory-produced materials (some of which required sensitising by the photographer, but others were sold ready for use.) They were more common in Europe than in the USA. Volumes were not huge and production ceased around 1920. One particular use of such materials was to make a cheaper alternative to the platinum print, gaining a similar neutral matt appearance by making a salted paper print and then using platinum toner.
Salted paper was again revived in the 1970s and later, by photographers who wanted to explore a greater range of possibilities than that offered by commercial materials. All make use of hand-coated materials, usually following one of the many thousands of methods published in earlier years.