ambrotype

photography

Also known as: positive on glass

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

June 18, 2026

Quick Summary

An ambrotype is a photographic process that creates a positive image on glass backed by a dark surface. This technique was developed as a modification of the wet collodion process, invented by Frederick Scott Archer in 1851. The wet collodion process involved coating a glass plate with a mixture containing collodion and iodide, then sensitizing it with silver nitrate. The plate, kept wet, was exposed in the camera and then developed and fixed.123

Ambrotypes were essentially underexposed or bleached negatives that appeared positive when viewed against a dark background. While popular from the mid- to late 19th century, they did not achieve the same brilliance as daguerreotypes. A similar, less expensive variation was the tintype, which used a black lacquered metal sheet instead of glass.23

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

3 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

tintype
…essentially a variation on the ambrotype, which was a unique image made on glass, instead of metal. Just as the ambrotype was a negative whose silver images appeared grayish white and whose dark backing made the clear areas of shadows appear dark, so the tintype, actually negative in its chemical…
Read More
…essentially a variation on the ambrotype, which was a unique image made on glass, instead of metal. Just as the ambrotype was a negative whose silver images appeared grayish white and whose dark backing made the clear areas of shadows appear dark, so the tintype, actually negative in its chemical…
Read More

history of photography
Development of the wet collodion process
…positive images on glass called ambrotypes, which were simply underexposed or bleached negatives that appeared positive when placed against a dark coating or backing. In pose and lighting, these popular portraits were similar to daguerreotypes in sizes and were enclosed in similar types of cases. They did not approach the…
Read More
…positive images on glass called ambrotypes, which were simply underexposed or bleached negatives that appeared positive when placed against a dark coating or backing. In pose and lighting, these popular portraits were similar to daguerreotypes in sizes and were enclosed in similar types of cases. They did not approach the…
Read More

Frederick Scott Archer
Archer also invented the ambrotype, a cheap form of portraiture, in collaboration with another photographer, but, having devoted all his funds to research, he died in poverty.
Read More
Archer also invented the ambrotype, a cheap form of portraiture, in collaboration with another photographer, but, having devoted all his funds to research, he died in poverty.
Read More

wet-collodion process
…form what was called an ambrotype, became very popular from the mid- to late 19th century, as did a version on black lacquered metal known as a tintype, or ferrotype.
Read More
…form what was called an ambrotype, became very popular from the mid- to late 19th century, as did a version on black lacquered metal known as a tintype, or ferrotype.
Read More