I found this article on the Internet and thought that some of you who appreciate (and maybe even have a few) old photographs laying around in cardboard boxes or in desk drawers might like to read some tips on ways to try to put a date on when they might have been brass decorative frame.This sealed packet was then force fit into a special wood case and was often padded with velvet or silk. The first step was to make a negative image on a light sensitive paper.The stamps date these photographs to the period of the Wartime Retail Tax Act, 1 Sept. They were popularized under the trade name Gem and the Gem Galleries offered the tiny likeness at what proved to be the lowest prices in studio history.Many times, the silver image tarnishes with silver sulfide in the same way as silverware. Step two was to make a contact [print] with a second sheet of sensitized paper to make a positive print. As the public sought lower prices, the cases (which cost more than the finished photographs) were eliminated.The cost: .00 (more than a weeks pay for most people). Calotypes were never widely popular, and most of those surviving are in museums. In their place, paper folders of the size of the then popular card photographs were used for protection.Apparently Talbot (the inventor) did not fully realize the importance of washing his prints long enough to remove all the residual chemicals, or perhaps his fixing was inadequate. Instead of a glass cover, the photographer covered the tintype with a quick varnish to protect any tints or colors added to cheeks, lips, jewelry or buttons.
After 1863 the paper holders were embossed rather than printed. During this period "rustic" photography also made its debut with its painted backgrounds, fake stones, wood fences and rural props.
Uncased tintypes have been found with canceled tax stamps adhered to the backs. Neither the chocolate tint nor the rustic look are to be found in pre 1870 tintypes. Tiny portraits, 7/8 by 1 inch, or about the size of a small postage stamp, became available with the invention of the Wing multiplying cameras.
Many are found in gilt frames or in the leather or plastic (thermomolded) cases of the earliest ambrotypes.
Size range from one-fourth plate and are often datable by the Potter's Patent paper holders, adorned with patriotic stars and emblems, that were introduced during the period.
Similar to daguerreotype in assembly of parts: 1-Disadvantages of ambrotypes: 1. sold for a penny or less, making photography universally available. It is sometimes confused with ambrotypes and daguerreotypes, but is easily distinguishable from them by the fact that a tintype attracts a small magnet. The earliest tintypes were on heavy metal (0.017 inches thick) that was never again used.A very slow (up to 20 sec.) exposure, compared to 2 sec. The cost of an image at the time the process became obsolete was about 25 cents. They are stamped "Neff's Melainotype Pat 19 Feb 56" along one edge.