Salt paper process

The earliest photographic process for making positive prints, invented by William Henry Fox Talbot in 1840. The print was made on high quality writing paper that had been immersed in a solution of common salt and then floated in a bath of silver nitrate. A finished salt print is matt in finish, reddish brown in colour, and has no surface gloss. It could be toned with a gold chloride for a richer, purplish tone and greater permanence. Salt prints were superceded by albumen prints in the 1850s.