Calotype

Calotype or talbotype is an early photographic process introduced in 1841 by William Henry Fox Talbot,[1] using paper[2] coated with silver iodide.

Talbot made his first successful camera photographs in 1835 using paper sensitised with silver chloride, which darkened in proportion to its exposure to light.

The calotype process produced a translucent original negative image from which multiple positives could be made by simple contact printing.

This gave it an important advantage over the daguerreotype process, which produced an opaque original positive that could be duplicated only by copying it with a camera.

Unlike Talbot, Daguerre who had been granted a stipend by the French state in exchange for making his process publicly available, did not patent his invention.

[5] In Scotland, where the English patent law was not applicable at the time, members of the Edinburgh Calotype Club and other Scottish early photographers successfully adopted the paper-negative photo technology.

[5][9] Nevertheless, calotypes—and the salted paper prints that were made from them—remained popular in the United Kingdom and on the European continent outside France in the 1850s, especially among the amateur calotypists, who prized the aesthetics of calotypes and also wanted to differentiate from commercial photographers,[10] until the collodion process enabled both to make glass negatives combining the sharpness of a daguerreotype with the replicability of a calotype later in the nineteenth century.