The true inventor of the tintype process is unclear. Many scientific discoveries contributed to the final product. Swiss chemist C.F.Schonbein discovered “guncotton,” or nitrated cotton in 1846. In 1847, John Parker Menard made it into a medical dressing called collodion by dissolving it in a mixture of alcohol and ether. In 1850, either Robert Bingham or Fredrick Scott Archer suggested it could be applied to photographic plates as it seemed to be the perfect binder for holding light-sensitive silver halide solution onto glass, and later metal. Frenchman A.A. Martin claims to have invented the tintype in the early 1850s, while Hannibal L. Smith did the same in 1856.
Although there are many differing names and dates associated with tintypes, it is certain that its development was tied directly with the development of collodion and ambrotypes. “Collodion” came from the Greek work meaning glue-like, and dried into a durable and flexible skin when applied to battlefield wounds during the Crimean War. Ambrotypes used glass as the emulsion support, while tintypes use metal plates. Ambrotypes and tintypes both needed surfaces that were japanned (lacquered) black or dark brown, so that the milky collodion formed the highlights and the unexposed areas showed the dark backing that provided the shadows. Tintypes have reversed images, but ambrotypes can be read correctly if blackened on the collodion side.
Since the material in tintypes was not tin, a more accurate but less used name was the “ferrotype.” Its physical appearance was gray and rather dingy. The images were one of a kind, and could not be reproduced. Tintypes were not fragile, so were often mounted in paper folders instead of the miniature cases that were needed to protect ambrotypes. The most common size for a tintype was 2 ¼ x 3 ½, but they were made in various sizes. The limiting factor was the size of the camera back.
At first tintypes were made with wet collodion. Photographers coated their own plates by hand with the substance, dipped them in silver nitrate, and exposed them while still wet. The mixture was both toxic and flammable and could cause an explosion. Final prints were usually varnished for protection.
Early tintypes were used in a documentary fashion. They were very small, sturdy, and were easy to carry in a pocket or bag. Soldiers during the Civil War had tintypes made at the battle front for relatives as evidence that they had existed. Pioneers headed west for new beginnings left tintypes behind with their families as reminders, and carried images of loved ones with them on their journey. Even postmortem portraits were common. Tintypes documented a person’s existence in the 1860s.
In the late 1870s, dry-plate (gelatin) was introduced, making the tintype more available, safer, affordable and popular to the general public. It played a substantial role in the democratization of photography. Even the working class could afford a tintype. Instead of a thirty-minute exposure with head clamps and baby holders, a sitter could have an image in a matter of minutes. Street photographers used the dry-plate process because it was cheap, fast, rugged, and easier to produce. They used cameras equipped with multiple lenses to make numerous small copies of the image for the sitter to give as calling cards. They could develop the plates in trays inside the bellows of the camera itself. It was a one-stage process without a negative, similar to a photo booth of today.
With improved equipment, less complicated processes and less cost, photographers became more willing to experiment with the medium. By adding a few props or backdrops, a photographer could transform a stark indoor photography studio into an outdoor fantasy or even the Statue of Liberty. People’s attitudes shifted as images became spontaneous, humorous and casual, thus the precursor of the snapshot. Tintypes were quite common in the late 1850s through the beginning of the 20th century, but during World War I, metal became precious, and paper prints from the Kodak Brownie camera made tintypes almost extinct.