The Wet Plate process is a photographic process, widely used to produce negatives
but also employed in a modified form to produce positives (ambrotypes and
Invented by Frederick Scott Archer of England in 1851
A piece of clear glass is coated with a very thin layer of iodized
collodion (made from gun-cotton (nitrocellulose) dissolved in ether
and alcohol, mixed with potassium iodide). The coated plate is dipped
in a silver solution in the darkroom which makes it light-sensitive.
After this, the plate must be immediately exposed in a camera. The exposure
needs to be completed before the chemicals on the plate have time to dry
out--hence "Wet Plate"
After development and fixing, the negative can be printed on any material.
Most wet plate negatives, however, were used to make prints on albumen paper.
Read more about Photographic Processes