The tintype: two patents, two Kenyon classmates, and a name neither man chose

By Matthew Partsch · Owl and Twig Vintage · September 30, 2026

Hamilton Smith patented the process in February 1856. Eight months later, his own former student patented a rival version and tried to get the market to call it something else entirely. The name that actually won belonged to neither man — and the same test that authenticates an 1860s original still catches a photographer’s brand-new one.

What a tintype actually is

A tintype is a thin sheet of iron, coated with a black lacquer called japan (raw linseed oil, asphaltum, and lamp-black, heated and polished), then coated again with light-sensitive collodion and exposed directly in a camera. There is no negative at any stage. The plate that comes out of the camera is the finished picture: the dark japanned surface reads as shadow, and the silver deposited by the exposure reads as highlight, so the image forms as a direct positive against the black background rather than being printed from a separate film. Because the plate is exposed the same way a mirror reflects, the resulting portrait is reversed left to right — a soldier photographed with a sword on his right hip is actually wearing it on his left.

That direct-positive process is also why a tintype could be handed to a customer minutes after sitting for it, at a fraction of the cost and weight of a daguerreotype on silvered copper or an ambrotype on glass. The plate is light enough to mail in an envelope, flexible enough to survive a coat pocket, and cheap enough that itinerant photographers at fairs, army camps, and street corners could sell finished portraits on the spot — which is the main reason the format survived, in shrinking but real numbers, from the 1850s into the 1950s.

The professor and his two students

Hamilton Lanphere Smith taught natural sciences at Kenyon College in Gambier, Ohio. Peter Neff met Smith there as a student, graduated in 1849, and later returned to the process after leaving the ministry for health reasons. The two worked out a way to apply collodion and silver salts directly to a black enameled iron plate rather than the far more expensive glass a daguerreotype or ambrotype required. Smith patented the process on February 19, 1856 — U.S. Patent 14,300, titled “Photographic Pictures on Japanned Surfaces” — and, according to Neff’s own biographical record, promptly sold the rights to his former student. By October 1856 Neff was manufacturing plates in Cincinnati, distributing instructional pamphlets, and selling licenses to photographers under the name he and Smith had coined: melainotype, from the Greek word for black.

Victor Moreau Griswold had also studied at Kenyon under Smith before switching from law to photography and opening his own studio in Lancaster, Ohio. Eight months after Smith’s patent, on October 21, 1856, Griswold filed his own patent — U.S. 15,924, “Bituminous Ground for Photographic Pictures” — covering a different bitumen-based method of preparing the plate’s surface. The two patents did not directly conflict: Neff’s covered the image-making process itself, while Griswold’s covered a specific way of preparing the plate a photographer exposed the image onto. That kept the dispute between two Kenyon classmates out of court and into the marketplace instead. Griswold's thinner, cheaper plates pushed Neff to drop his own licensing fees to stay competitive, and the rivalry between the professor's two students is a large part of why tintype prices fell fast enough to make the format a mass product rather than a novelty.

Neither man was first to describe the underlying idea. In April 1853, a French chemist named Adolphe-Alexandre Martin sent a paper to the French Academy of Sciences describing how a colored varnish, applied over a photographic negative on glass and later on metal, could chemically convert that negative into a positive image — the same optical trick a tintype's black japanned surface performs by default. Martin's paper was published in the journal La Lumière and drew attention across Europe. He does not appear to have patented the technique or built a business on it. Smith and Neff's American patent, three years later, is the one that turned the idea into an industry.

The name nobody who made it picked

Smith and Neff called their product melainotype. Griswold called his ferrotype, and he cared enough about the distinction to put it in writing: the name the public was actually using, he objected, was “senseless and meaningless,” since “not a particle of tin, in any shape, is used in making or preparing the plates.” He was correct on the chemistry. The plate is iron, not tin, from the first patent to the last one filed in the format's working lifetime.

Tintype won anyway, and it has stayed in use for a century and a half since, through trade catalogs, family albums, and today's auction listings. The myth Griswold was fighting is still alive in exactly the form he complained about: a current eBay listing for an ordinary sixth-plate soldier portrait describes it as “real tin, not a paper photograph” — the identical misconception, in almost the identical words, a competing inventor was correcting in print in 1856.

How to date a tintype

No single feature dates a tintype precisely on its own, but several, stacked together, narrow a window considerably.

• 1850s. Plates from this decade tend to be heavier-gauge iron, usually protected in the same hinged, velvet-lined cases sold for daguerreotypes and ambrotypes — cases cost more than the plate did, so as tintype prices fell through the 1860s, the case largely disappeared.
• Early-to-mid 1860s. Cheap paper sleeves and folders, sized to match the popular carte-de-visite format, replace the case. Patriotic star-embossed paper holders sold under the name “Potter's Patent” date to 1863 and after.
• 1863 onward, gem tintypes. Simon Wing's multiplying camera could expose many tiny portraits — roughly 7/8 by 1 inch each — on a single iron sheet in one sitting, which a studio then cut apart into individual gems for mounting in a locket or an album page. The National Museum of American History holds an uncut sheet of nineteen gem portraits from a single exposure, with only one of the original twenty cut away — a rarer survival than any single gem, since cutting the sheet apart was the normal next step, not an accident.
• August 1, 1864 to August 1, 1866. A federal tax on photograph sales required a revenue stamp on the back of the print. No dedicated photograph stamp existed, so photographers pressed ordinary proprietary or playing-card revenue stamps onto tintypes and signed or dated across them by hand. A canceled stamp, especially a dated one, pins a plate to this two-year window almost exactly — the same tax, and the same dating trick, that applies to paper mounts from the same years, covered in this shop's stereoview card guide.
• 1872 and later, named studio finishes. Albion K. P. Trask's trade manual Practical Ferrotyper (Philadelphia and London, Benerman & Wilson, 1872) illustrates a “chocolate tinted egg-shell plate” finish as a named, deliberate studio product — evidence that the warm brown tone seen on many later tintypes is a manufacturing choice from at least the early 1870s forward, not simply age or fading. Unlike the revenue stamp, this is a floor rather than a fixed date: it confirms a plate is 1872 or later, not which later year.

How to tell a real one

A magnet is the fastest test available, and it works because of what the plate is actually made of: thin iron, not tin, coated in lacquer. Hold a small magnet near the back of an unmounted plate, or near the edge of one still in its case or sleeve, and an authentic period tintype pulls toward it. Neither a daguerreotype's silvered copper plate nor an ambrotype's glass plate will respond at all.

Two further checks separate a tintype from its closest period relatives. A daguerreotype's surface is mirror-bright, and tilting it under a light source flips the image between a visible positive and a ghostly negative — no other format does this, which makes the tilt test close to definitive on its own. An ambrotype is glass with a dark backing (paint, paper, or velvet) behind it; held up to a strong light, the edges show translucent glass, and if the backing can be removed, the image itself reads as a photographic negative once the dark backing is gone. One caution worth carrying into any of these tests: the Library of Congress's own guide to the format notes that a sheet of metal placed behind an ambrotype as backing could, in principle, fool a magnet test performed carelessly — so the magnet is the fastest check, not the only one, and a glass edge or a tilt test is worth confirming alongside it rather than instead of it.

The look-alikes

Where the records disagree

What tintypes sell for

Realized prices for tintypes are inconsistent to track down — most marketplace listings show only an asking price, and several auction-result pages that display a sold price require a paid account to view it. The figures below are labeled by exactly what each one is.

At the low end, an anonymous sixth-plate or ninth-plate soldier portrait with no identifying information asks in the range of ten to fifteen dollars on eBay — the listing behind this guide's naming-dispute section, in fact, priced at $14.95 with a coupon. A sixth-plate Civil War soldier portrait with a hand-tinted flag background realized $124 at Britannic Auctions in December 2022, a genuine sold price rather than an asking one. At the high end, condition and plate size matter far less than who is actually in the picture: a gem-sized tintype identified as a portrait of Abraham Lincoln, mounted on a period carte-de-visite card, sold for $550 through the dealer Horse Soldier. The same tiny format that survives in anonymous multiples for a few dollars each is the same format that, attached to the right name, commands forty times as much.

For a look at the other major nineteenth-century photograph-on-paper format and the same federal tax window from the mount side rather than the plate side, see this shop's stereoview card guide. For a later photographic format built for the mass market tintype helped create demand for, see the real photo postcard guide. See more Field Guides

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