Here are some examples of testing I did for Tin Type photography alternative process. I had the possibility of being asked to do tin types for a production, it did not end up happening. These tins are the results of my testing and becoming competent in making these delicate images.
Tin types are post Civil War photographic technology that first appeared in 1855, peaked around 1870 and was mostly out of use by the turn of the century. The image is created by making a negative image on a black aluminum plate. As in traditional black and white film negatives, dark areas of the image are lighter & clearer on the negative while the lighter areas of the images appear black or darker in a negative. What you see in a tin type is the “negative” letting the dark areas of the black plate show through and the room lighting showing the black or darker parts of the negative as white or lighter. You can sometimes get the same effect by looking at a film negative against a black background.
The process I use to make tins is to prepare the 4×5 plates in a darkroom with a fairly bright red light (the emulsion is not sensitive to red light at all, which makes for some unusual looks and exposures). The emulsion is a gel at room temperature so I warm the emulsion in a hot bath. After it has warmed I pour some on the black plate and roll it around to evenly cover the plate and then let it dry. I then load one plate in typical 4×5 film holders a friend of mine machine to accept the plates. The plates are good to use for a day or so. I then load the film holder into my Speed Graphic press camera with a Fugi 210mm, expose for 1 ISO and then back into the darkroom. It is pretty much typical film processing after that. Develop, fix and wash. I use Glad sandwich containers for chemical trays as the plated fit perfectly.