fox-talbot and the talbotype

The Talbotype, or 'Calotype' (its proper name) was invented by William Henry Fox Talbot in 1840. Although talbot did not intend it as such, It was seen as a simpler alternative to the complicated Daguerreotype process, and was attractive to early practitioners due to its relative simplicity.

The Calotype is technically the negative image on made paper, but its positive counterpart, the salted paper print, is the more common form in which calotypes are encountered. Calotypes are made by brushing paper with a solution of silver nitrate and then immersing it in a solution of potassium iodide to form a light-sensitive layer of silver iodide. Exposure in a camera produces a latent (invisible) image which is developed, fixed in hypo and washed. The translucency of Calotypes can be improved through waxing, and a positive can be made by printing out the image in a printing frame.

The Calotype was never commercially successful and was all but forgotten within ten years, having given way to the wet collodion (glass negative) and the albumen printing processes.