Until 1850, the earliest prints were salt-paper ones. They were made by coating sheets of paper with salt dissolved in water, and then sensitising the paper.
Salted papers were not subjected to development. They were printed out; that is to say they were contact prints, placed in a frame with the negative, but left to print out in the sun, a process that would take approximately thirty minutes. It would then be fixed in the normal way.
Because the paper had been sensitised in this manner, the image was in
the paper, rather than on it. The texture of the paper, then, also appeared on the
image, and this caused a loss of definition. Some actually preferred this, and were not
taken by the glossy appearance of the albumen paper which began
to supersede it (see for example Shadbolt), preferring the
matte form of salted-paper.
© Robert Leggat, 1997.