I have, very slowly collected Tin Types since a trip to a flea market in New York many years ago. I had never seen them before and found them fascinating. They are made on really thin sheets of iron rather than tin, they were informally named tin types due to feeling like tin. I love all things old, metal and fascinated by people and their (potential) stories, so these were perfect.
Tin Types began in the 1850's in the US and called Melainotypes at first until a rival producer making a similar product named theirs Ferrotypes. They arrived in the UK around 20 years later and generally continued into the 1950's. All shortly after glass and silver were used, but Tin Types were a quicker process for the photographer and cheaper to produce. I love this simple quality, like postcards, most people could access them.
They are a lovely intriguing dark image due to their process and sometimes framed in a decorative card mount. I have a couple of, I believe, the same person, (see main image) with the photographers details on the back (last image) but unlike vintage calling cards they don't oten have this information.