Calotype

The calotype, also called the talbotype, is an early photographic process, introduced by William Henry Fox Talbot in the early 1840s, that uses paper coated with silver iodide to produce a translucent paper negative. Unlike the daguerreotype, which produced a single unrepeatable image directly on a metal plate, the calotype's paper negative could be used to make multiple positive prints, establishing the negative-to-positive principle that underlies most photography since. The texture of the paper fibers gives calotype prints a characteristically soft, slightly grainy quality distinct from the crisp fine detail of a daguerreotype. Talbot introduced the process publicly in 1841 and patented it in England, and despite the ease with which calotypes could be made, the patent restriction was a major reason the process never displaced the more sharply detailed and unpatented daguerreotype in popularity; the English patent was not lifted until 1853, twelve years after the process reached the public.