Tintypes were an extension of the Ambrotype process, but produced on a metal plate instead of glass. They are not actually made of tin, but rather a ferroous or iron based metal, hence they are also (more accurately) referred to as 'ferrotypes' and as Melainotypes, which was what they were called when first introduced, around 1856. It was Professor Hamilton Smith (Kenyon College in Gambier, Ohio) along with Peter Neff who adapted the Ambrotype process to work with iron plates.

The earliest tintypes were cased in the same type of frame as Ambrotypes and Daguerrotypes, but usually without the glass. They also tended to be on heavier gauge iron plates, having been imported from Europe.

They had several advantages over the Ambrotype:

• They were less fragile, so easier to handle, mail, or carry in the pocket.
• It was a simpler, one step process that involved no negative. They were easier for non-technical and street photographers to produce.
• They were cheap. The low cost of materials and finished product brought photos to the masses, whereas it had been more special occasion oriented previously. Likewise, the business start up cost was low, encouraging
• It was a much faster process.
• They could be easily cut to any size or shape.

Tintypes were produced in a number of sizes. The most common was about the same as a CDV, 2.5" x 3.5" or 4". They were individually cut by the photographer with tin shears, which may be responsible for the misnomer.
 

 

Common Tintype Sizes

Gem	.5" x 1"
Sixteenth Plate	1.6" x 2.1"
Ninth Plate	2" x 2.5"
Sixth Plate	2.5" x 3.5"
Quarter Plate	3.125" x 4.125"
Half Plate	4.5" x 5.5"
Full Plate	6.5" x 8.5"

Dating Tintypes

Earliest Tintypes: 1856 - 1860.
The first tintypes were on heavy black Iron (about 0.017 inches thick) which was imported from Europe and not used on later tins.  They are stamped "Neff's Melainotype Pat. 19 Feb 56" on the edge. They are often found in gilt frames or in the leather or plastic (thermomolded) cases like the early ambrotypes. Sizes ranged from one-sixth plate to full plate. (2.5" x 3.5" to 6.5" x 8.5").

Civil War Era Tintypes: 1861 - 1865.
Most Tintypes of this period were one-sixth and one-fourth plate and were frequently sold in Potter's Patent paper holders, often  adorned with patriotic stars and emblems, which were introduced during this period. After 1863 the paper holders were embossed rather than printed. Uncased tintypes have been found with canceled tax stamps adhered to the backs. The stamps date these photographs to the period of the Wartime Retail Tax Act, which was in effect from September 1, 1864 until August 1, 1866.

The Brown Period: 1870 - 1885.
The Phoenix Plate Co. began making plates with a chocolate-tinted surface in 1870. They quickly found favor with photographers throughout the country, and the photos made on the chocolate-tinted plates soon became very popular. Another development during this time period was the 'rustic' style of photography, which included wood fences and other rurlal props, fake stones, and painted backdrops. If your tintype has either the chocolate tint or the rustic elements mentioned, you can be fairly certain that is post 1870.

The Gem Tintype Period: 1863 - 1890.
In about 1863 it became possible to produce a number of tiny portraits on a single plate, using the Wing multiplying camera. At 7/8 by 1 inch, they were  about the size of a small postage stamp. They were marketed under the trade name Gem. Gem Galleries offered the tiny photos at the lowest prices yet. Gem Galleries were common until about 1890, when  roll film and family cameras made their debut, allowing more freedom to create larger images at low cost, without the need to visit a studio.. Gem portraits were commonly stored in special albums with one portrait per page. Slightly larger versions also existed. Gems could be cut to fit lockets, tie pins, rings and even cufflinks and garter clasps.

The Carnival Period: 1875 - 1930.
Itinerant photographers frequently brought the tintype to public gatherings, such as fairs and carnivals. They came equipped with painted backdrops of Niagara Falls, a beach, a boat, and other novelty props for comic portraits.