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.
A number of photographers, working with larger field cameras, created slightly larger cards of 4" x 7", 4 3/8" x 7" and 4 1/2" x 7".Until about 1873 the smaller sizes were sold at twenty five cents per card and the larger "artistic" size for fifty cents.Within a decade sets of twenty or more were made on printing presses, not by a hand photo-plate negative, look for an uneven coating were the syrupy colloidal base of the glass plate did not flow to the very edges of the glass.Wet plate negatives were often 11" x 14" up to 20" x 24" sheets of sensitized glass.plate photographers helped to open the American West by taking their cameras out of the studio and on location assignment with the survey teams of the U. Government and the railroads in the Far West, and with the geological expeditions moving into the unmapped wilderness beyond the Rocky Mountains.The giant spaces they discovered demanded giant cameras.
The camera that documented the famous meeting at Promontory Point, Utah of the tracks of the Central Pacific and Union Pacific railroads on was built to accommodate glass plates 10" x 13".
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.
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.
This led to verbal skirmishes between photographers who insisted in "truth in photography". The stamp was to be canceled by requiring that the seller cancel the stamp by initializing and dating it in ink.