Introduced by Fredrick Scott Archer in 1851, the silver collodion process quickly took the world by storm, becoming the dominant method of creating images. It allowed a photographer to have a mobile set up where in he could create a likeness of a subject almost instantly and on demand. The process is not easy by any means. It requires the hand preparation of each individual plate. Coating it with collodion, a solution of gun cotton in ether and alcohol, sensitizing the plate in a solution of silver nitrate, in the dark, exposing the plate, then developing it, all while the plate is wet. All within fifteen minutes or so. After developing, washing and drying the plate, it is then heated over an alcohol lamp and varnished. A solution of gum sandarac, lavender oil varnish is poured over the plate then allowed to dry. It smells wonderful. This is a difficult, time consuming, costly process, with many chemicals, materials and steps. It is the opposite of digital photography. This is partly why it's so appealing. The necessity to slow down, think about what you're woking on, being present and deliberate. The result, is a beautiful, unique, one of a kind image that cannot be reproduced aside from scanning it electronically. It may have the tell tale marks around the edges, dust, artifacts, comets, spots, finger prints and other character building "flaws". All part of the beauty.
The tintype has the most elemental silver content of any photographic process. The images are extraordinarily archival. Many plates from the 1850's are still around. It is as of yet unknown how long they will last, but they will certainly out live you, and probably your grand children.