Although not an historic process, Lith printing is considered an alternative photograhic process which has been championed by the master of the technique, Dr. Tim Rudman. It is written on the jacket of his seminal instruction guide The World of Lith Printing, that Rudman "controlled what was often described as a wayward and uncontrollable process."
A negative is exposed onto photographic paper through an enlarger then developed in a highly diluted lith (high contrast) developer. Development occurs by what is termed 'infectious development.' As tonality becomes darker, development becomes faster; darker, faster, darker, faster, & on it goes, making the determination of the 'snatch point' crucial and often difficult to see under the red-light of the darkroom. Once 'snatched' from the developer, the print follows the route of traditional darkroom printing practices - stop bath, fixer, hypo and finally a water clearing bath.
source: Tim Rudman
One of the oldest photographic processes, Salted Paper was perfected by William Henry Fox Talbot in 1839 and most heavily used between 1840 - 1855. Fox Talbot called his images on salted paper 'calotype,' meaning "beautiful picture."
POP, printing out paper, was and still is treated with a chloride (salt) before being sensitized with a silver nitrate solution. Once the sensitized sheet is dry, it is placed, with negative on top, in a contact printer. This printer assures there will be no slippage of the negative during exposure. The hinged printer also allows for checking exposure times.
Exposures can be made under UV light, however, I choose to expose in the sun. This means very little consistency of exposure time as the sun is forever moving and changing distance as well as intensity from hour to hour and season to season.
Once properly exposed, the paper is rinsed, under safelight conditions, repeatedly in water to dislodge and remove any excess unexposed silver salts. After clearing, the print is fixed in a sodium thiosulfate bath.
source: Robert Farber
