If you have inherited a box of family pictures, there is a chance a few small, dark portraits on thin metal are mixed in with the paper prints. Those may be tintypes. They were widely used for portraits in the nineteenth century, and many families still own one without knowing what it is. This guide explains what a tintype is, how it was made, how to tell it apart from the other early photo types, and how to store it so it survives another century.
What is a tintype?
A tintype is a photograph made directly on a thin sheet of metal. In technical terms, it is a direct positive: there is no separate negative, and the plate that sat in the camera is the finished picture. Despite the name, the metal is not tin. The support is a thin sheet of iron coated with a dark lacquer or enamel (often called "japanning"), which carries the light-sensitive layer.
Tintypes went by several other names over the years, including melainotypes (or melanotypes) and ferrotypes. These names refer to the same general kind of direct-positive photograph on a dark metal support.
How tintypes were made
Most tintypes were made with the wet collodion process. The photographer coated the lacquered plate with collodion containing light-sensitive silver salts, sensitized it, and exposed it in the camera while the coating was still damp. The image on the plate is actually a heavily underexposed negative. Because the thin silver deposits look pale against the black lacquer behind them, the eye reads the picture as a positive. A later "dry" version used a gelatin emulsion that did not have to be exposed wet.
Two practical consequences follow from this process:
- Each tintype is usually one of a kind. Since there is no negative, a tintype could not simply be reprinted. Copies had to be re-photographed.
- A camera original can produce a laterally reversed image unless the camera used an optical correction. A part in someone's hair or the buttons on a coat may therefore appear on the opposite side.
A short history of the tintype
The process was described in France by Adolphe-Alexandre Martin in 1852–53. Hamilton L. Smith received a U.S. patent for a related process in 1856. Early tintypes used wet-collodion chemistry on blackened iron sheets. Gelatin-emulsion metal plates became commercially available around 1890–91, and “photo-button” tintypes were widespread from about 1890 to 1930; use declined sharply during the Depression and largely disappeared by the early 1940s.
How to tell if a photo is a tintype
Early photographs can look alike, especially when they sit behind glass in a small case. These checks help:
- Try a magnet. This is the most reliable test. Because the support is iron, a magnet will be attracted to a tintype. Both the Canadian Conservation Institute and the University of Illinois Preservation Self-Assessment Program (PSAP) describe the magnet as a way to identify a tintype's support; PSAP calls it the surest test.
- Look at the tones. Tintypes tend to be low in contrast, with tones from chocolate brown to sepia and milky-white highlights. Subtle hand-coloring is common.
- Check the housing. Some tintypes sit in small hinged cases, but more often they come in folding cards or envelopes, in paper or metal window mats, or loose.
- Measure it. Sizes were standardized. The sixth-plate (about 2½ x 3½ inches) was the most common; tiny "gem" tintypes are about 1½ x 1½ inches or smaller.
Tintype vs. ambrotype vs. daguerreotype
| Type | Support | Quick clue |
|---|---|---|
| Tintype | Lacquered iron sheet | Attracts a magnet; often loose or in a paper sleeve |
| Ambrotype | Glass, with a dark backing | Can look similar in a case, but a magnet will not stick |
| Daguerreotype | Silver-plated copper | Highly polished, mirror-like surface (Oliver Wendell Holmes called photography "the mirror with a memory" in 1859); usually kept in a hinged case; older and more costly than a tintype |
How to care for and store tintypes
Tintypes are more durable than daguerreotypes, but they have one main enemy: moisture and high humidity. Moisture lets the iron rust, which leads to blistering, flaking and loss of the image layer.
Conservation guidance points to a few simple habits:
- Keep them cool and dry. The Canadian Conservation Institute recommends relative humidity between 30% and 50%, never above 60%, and storage temperature no higher than 24°C (about 75°F), ideally below 21°C. The Library of Congress also advises against storing photographs in attics and basements because of condensation, leaks and temperature swings.
- Give each one its own enclosure. Use an individual acid-free enclosure for each loose tintype. The Library of Congress says photo-safe enclosure materials should meet the requirements of ISO 18902, which include passing the Photographic Activity Test. If the emulsion is already flaking, store the plate flat and keep humidity low.
- Cased tintypes can be wrapped in acid-free tissue and kept in a folding box.
- Do not flex them. The iron is often very thin (about 0.15 mm), and loose tintypes are frequently dented, bent or scratched.
- Handle with clean lint-free nylon or cotton gloves, holding the plate by its edges.
- Limit display. Light can make the collodion and varnish yellow. PSAP suggests keeping light as low as possible, avoiding direct natural light, and limiting a display to about 3 to 4 months before returning the item to dark storage.
How to clean a tintype
Very little. The Canadian Conservation Institute's guidance for cased photographs is that only loose dust should be removed, with a soft brush or gentle air, and that no other cleaning method can be recommended safely for the image itself. For a valuable or badly rusted plate, ask a photograph conservator.
Make a copy before anything else
Because most tintypes are unique, the single best thing you can do for a family tintype is to digitize it. A flatbed scanner works well. The Library of Congress says documents should generally be scanned at 300 dpi, and photographs you intend to enlarge to 8 x 10 inches or greater can be scanned at 400 or 600 dpi (anything above 600 may be unnecessary). Give the file a descriptive name (who, where, approximate date), make at least two copies, store them in different locations, and then return the original to dry, dark storage.
Sources
- Wikipedia, "Tintype": https://en.wikipedia.org/wiki/Tintype
- Canadian Conservation Institute, "Care of Encased Photographic Images" (CCI Notes 16/1): https://www.canada.ca/en/conservation-institute/services/conservation-preservation-publications/canadian-conservation-institute-notes/care-encased-photographic-images.html
- University of Illinois Preservation Self-Assessment Program, Format ID Guide, "Direct image / tintype": https://psap.library.illinois.edu/format-id-guide/directimage
- Library of Congress, "Scanning Your Personal Collections" (Personal Digital Archiving series): https://www.digitalpreservation.gov/personalarchiving/documents/scanning_collections.pdf
- Library of Congress, "Care, Handling, and Storage of Photographs": https://www.loc.gov/preservation/care/photo.html
- Harvard Gazette, "The mirror with a memory": https://news.harvard.edu/gazette/story/2013/04/the-mirror-with-a-memory/