Friends Historical Library cased photographs collection

Cased photographs are a class of photographs common in the mid-19th century mounted in a shallow, hinged box. Typically ambrotypes and daguerreotypes. The case provided protection for fragile processes. The cases were often made of wood with a tooled leather, paper, or cloth cover, or from an early molded composite (see union case).

A daguerreotype is a photograph made on a silver-coated copper plate and developed using fumes of mercury. Invented by Louis Jacques Mandé Daguerre in the late 1830s and announced publicly in 1839, daguerreotypes were the first practical photographic process. They remained common until the popularization of the ambrotype in 1854. The surface is highly reflective. The image appears as a positive when viewed while reflecting a dark background and as a negative when reflecting a light background. The image is monochromatic, although color may have been added by hand. Unless special camera optics were used, the image is laterally reversed. The surface is fragile and may be tarnished. To protect the image, a daguerreotype is almost always mounted under glass with a paper seal around the edge; most daguerreotypes are mounted in a hinged case.

An ambrotype is an underexposed, underdeveloped, wet-collodion negative on glass that, when viewed with a dark background, appears as a positive image. The dark background is commonly a black varnish applied to the glass base but is sometimes a separate material behind the glass or the glass base itself may be dark. The same process using a black-varnished metal plate is known as a tintype. Ambrotypes were patented in 1854 by James Ambrose Cutting and were common through the 1870s. They largely supplanted daguerreotypes.

Citation: Richard Pearce-Moses, "A Glossary of Archival and Records Terminology," Society of American Archivists, 2005. https://www2.archivists.org/glossary