Who invented the early photographic print processes known as Calotype?

William Henry Fox Talbot (1800 - 1877) was a British landowner, scientist, archaeologist, politician and a photography pioneer who invented the calotype process, one of the earliest photographic processes. In this technique, a sheet of paper coated with silver chloride was exposed to light in a camera obscura; those areas hit by light became dark in tone, yielding a negative image.

It was not Talbot's first photographic process (introduced in 1839), but it is the one for which he became most known. Henry Talbot devised the calotype in the autumn of 1840, perfected it by the time of its public introduction in mid-1841, and made it the subject of a patent (the patent did not extend to Scotland).

This process uses a paper negative to make a print with a softer, less sharp image than the daguerreotype, but because a negative is produced, it is possible to make multiple copies. The image is contained in the fabric of the paper rather than on the surface, so the paper fibers tend to show through on the prints. The process was superceded in the 1850s by the collodion glass negative. Because of Talbot's patent rights, relatively few calotypes were made in the United States.