Tintypes are made with black aluminum. After being cut to size, salted collodion is poured onto the plate. It is then immersed into silver nitrate. While the plate is still wet, it is exposed in the camera with my Voigtländer-Petzval 1846 lens. After exposure, each plate is immediately returned to the darkroom for development and fix. The last step is to varnish the plate with sandarac lavender oil that is applied by hand and warmed over an alcohol lamp. Each tintype is one of a kind by the inherent nature of the process and possess small imperfections which make each plate unique. Tintypes can potentially last up to 150 years. Plan to pass the plates down to future generations.
This is a simplified straightforward description of making a tintype but by no means should the process be taken lightly. If the chemistry is not handled appropriately, it can be hazardous, poisonous, extremely flammable, and can be explosive.