Guide to the Cased Photographs from The Bancroft Library and the California State Library
Guide to the Cased Photographs from The Bancroft Library and the California State LibraryThe Bancroft Library
University of California, Berkeley
- Encoded by:
- Michael Conkin
- collodion positive photograph on glass. The ambrotype plate is actually a
glass collodion negative that is underexposed or bleached. It appears
positive when viewed against a black backing, which was achieved using any
number of materials, including asphaltum applied to the plate, a blackened
metal backing plate, dark fabric, or use of a dark ruby or violet colored
glass. The process was patented in 1854 and was popular in the United States
until the middle of the 1860s. Like the daguerreotype, an ambrotype is a
unique image, the plate being exposed directly in the camera, therefore not
resulting from an intermediary negative.
- Clear glass:
- most common, with black backing to make the image appear positive.
- Colored glass:
- collodion on dark colored glass; may be red ("ruby"), violet, or blue in color. .
- In relievo:
- the black backing was not applied to the entire plate, but only behind the image area. A white or colored or patterned backing could then be added to appear as a backdrop and give a slight three-dimensional effect. .
- Cutting's Patent:
- a process intended to protect the image from water damage. The ambrotype plate was sealed to a second glass plate using a layer of balsam. The image plate's emulsion side faced the glass backing plate or cover plate. Usually, the image plate was on top, the backing plate was blackened with asphaltum, and no cover glass was used. Many examples of imitations or infractions of this patent have been found, with peculiar variations on the idea of sealing two glass plates together. A typical form of deterioration often visible is a fern-like separation of the image plate from the backing plate..
- black tar-like backing often applied to blacken the backs of ambrotype plates. Application methods varied, and it can appear as a thin varnish or a thick coating.
- Bare plate:
- term used in the current project to indicate an image plate without its preserver, mat, cover glass, or other packaging. Bare plates were photographed as part of the preservation treatment process when image details were revealed that would otherwise be obscured within the image package.
- see Salt Print.
- usual containment for cased photographs, typically made of leather over wood or paper over wood, thermoplastic, papier mache, velvet, or sometimes tortoise shell or mother of pearl. They generally are decorated with a motif or scene: geometric patterns, floral arrangements, and historical or mythological figures are typical. Thermoplastic "union cases" represent the earliest commercial use of plastic, and they date from 1853. These cases are often mistakenly referred to as "gutta percha", which is incorrect.
- Case motif:
- the decorative pattern on the exterior of the case. In the Bancroft cased photograph project, an attempt was made to identify cases and locate them in one of four reference sources on miniature cases. (See Bibliography for works by Berg, Krainik, and Rinhart). Under Case Notes on each item record in the finding aid, a motif has been described and, if it was located, the reference source was noted, followed by a code or plate number, such as "Rinhart 135". Users should note that Rinhart numbers 230 and higher are found in their work The American Daguerreotype rather than their American Miniature Case Art, which contains the lower plate numbers.
- Case well:
- the recessed area of a case that holds the image, generally on the right side as the case is opened. Double cases have two wells, with an image in each. The image package is set snugly in the well.
- Cloth photograph:
- see Pannotype.
- Cover glass:
- protective glass covering surface of daguerreotypes and most cased ambrotypes and tintypes. Cover glass was placed over the brass mat and, generally, sealed to the plate with a paper tape around its edges. The brass preserver was then placed around this package. Some ambrotypes were cased without cover glass, with the brass mat at the surface. For the Bancroft Library collection, a protective cover glass was added over the mat of such objects. See also: Salting.
- albumen photographic print (on paper) adhered to the inside of convex glass, waxed or oiled for transparency, and hand colored from behind. An additional convex backing glass may be added. This process was popular later than the cased photograph era, and examples date from the 1870s to ca. 1900 or later.
- photograph on silver-plated copper. This is the earliest viable form of photography, and its introduction is usually dated to 1839, although successful experiments in the process predate this by some years. It is named for Louis Jacques Mande Daguerre (1787-1851). A daguerreotype is a unique photographic object, the plate being exposed directly in the camera, with no intermediary negative and therefore no multiple "prints". It is "wrong reading" (the image is reversed) unless it has been copied, or a reversing prism was used. The daguerreotype was the dominant photographic process well into the 1850s, at which time the ambrotype, the tintype (also called the ferrotype), and the paper photograph contributed to its decline. The daguerreotype process was largely out of use by about 1860.
- Die maker (or die-engraver):
- the maker of the die cylinders (or molds, for thermoplastic cases) used to emboss a particular decorative motif in the leather, paper, or cloth case covering. Occasionally the name of the die maker appears in very small letters on case exteriors.
- see Tintype.
- Half plate:
- see Plate sizes.
- Image Package:
- term used in the present finding aid to refer to the elements immediately surrounding or sealed together with the image plate. The term is not in general use, but has been applied here as a matter of convenience. As a unit, the image package would be set in the case well. It may consist of some or all of the following: image plate, brass mat, cover glass, brass preserver, paper seal, and possibly a backing of glass, metal, paper, fabric, or other material.
- Image well:
- see Case well.
- Leather Photograph:
- collodion positive photograph on blackened leather, similar to a pannotype. In a case and under glass, they may be indistinguishable from tintypes and ambrotypes.
- see Photographer.
- brass mats are almost always present on cased photographs, and are usually sealed between the image plate and a cover glass.
- see Tintype
- Ninth plate:
- see Plate sizes.
- Opalotype (or Opal Picture):
- carbon transfer or collodion positive on white glass, known as milk glass or porcelain glass.
- the fabric surface inside the case cover, generally made of silk or velvet over batting. Velvet pads were often embossed with decorative motifs or the name and address of the photographer.
- collodion positive photograph on cloth (oil cloth or linen) blackened with asphaltum or similar black, waxy substance. They are closely related to leather photographs. In a case and under glass, they may be indistinguishable from tintypes and ambrotypes.
- Usually, photographers are not identified on cased photographs. Some blind-stamped their names and/or business addresses on their brass mats, and others embossed this information in the velvet pad within the case cover. Occasionally, a pencilled note is found on the paper lining of the case well. Names of case and mat manufacturers or die makers are sometimes found on cases and mats and must not be confused with photographers' marks.
- Plate (image plate vs. backing plate):
- plate, in the present finding aid, usually refers to the surface on which the image appears: the silver-plated copper plate of a daguerreotype, the glass of an ambrotype, or the iron plate of a tintype (or ferrotype). The term "backing plate" or "metal plate" was used for a piece of metal or glass added behind the image plate, either as a black ambrotype backing or for strength. (Cloth or paper was also used for this purpose.) See also: Plate sizes. .
- Plate mark:
- a stamped hallmark on a daguerreotype plate that identifies the manufacturer of the plate. Smaller plates cut down from whole plates may or may not exhibit plate marks. Plate marks typically bear a mark specific to the maker, and often a number (40) denoting the silver content. Marks are typically symbols (stars, eagles, lambs, etc.), initials, or company names.
- Plate sizes:
- Daguerreotype plates were manufactured to (or cut down to) standard sizes,
based on fractions of the whole plate. (Other sizes, such as one third or
two thirds plates were more commonly used in Europe.)
- Whole plate = 6.5 x 8.5 in.
- Half plate = 4.25 x 5.5 in.
- Quarter plate = 3.25 x 4.25 in.
- Sixth plate = 2.75 x 3.25 in.
- Ninth plate = 2 x 2.5 in.
- Sixteenth plate = 1.38 x 1.63 in.
- Preserver (Protector):
- the preserver or protector appears as the outermost brass frame around the image package. It is made of thin brass and is crimped around the edges of the image package, and is on the exterior of the cover glass. Daguerreotypes prior to the late 1840s generally did not have preservers, but they may also be lacking from later examples.
- see Preserver.
- Quarter plate:
- see Plate sizes.
- the edges of the case and case cover, framing the image package or the pad.
- Salted paper print (Salted paper photograph or salt print):
- early form of photographic print on paper, pre-dating the albumen print which was predominant in the 19th century. More common in England and Europe in the 1840s, most American examples date from the mid-1850s to early 1860s. Early European examples, termed Calotypes or Talbotypes (invented by William Henry Fox Talbot), were printed from waxed paper negatives. Examples from the American West of the 1850s were usually printed from wet collodion glass negatives.
- typical deterioration obscuring daguerreotypes. Salting may have the appearance of beads of moisture (or "weeping") or of a dry, crystaline substance inside the cover glass. It is the result of condensation (resulting from temperature and humidity changes) interacting with the glass, and is generally composed of silica and sodium hydroxide. (See Barger and White, p. 175-181.) Usually it is on the cover glass and not the plate and can be easily removed by a conservator, atlhough it can cause damage to the plate itself.
- generally, strips of paper adhered with glue or paste around the edges of plates and cover glass to seal the image from the atmosphere. Sealing prevents tarnishing of daguerreotype plates. Original seals are often made from writing paper and may have fragments of annotations or other text on them. Archival filmoplast seals have been used to reseal image packages in the Bancroft Library collection.
- Sixteenth plate:
- see Plate sizes.
- Sixth plate:
- see Plate sizes.
- Tintype (or Ferrotype):
- collodion positive photograph on an iron plate. The process dates from the mid-1850s and, in different variations, was popular in the United States well into the 20th century. Given that the plate is iron and not tin, "ferrotype" is the technically accurate term. However, common usage in the United States is "tintype", and this is therefore the term preferred by the Library of Congress and in the present finding aid. The earliest American tintypes often bore "melainotype" or "Neff's Patent" markings on the plate. Like the daguerreotype and ambrotype, the tintype was a unique image, the plate being exposed directly in the camera, therefore not resulting from an intermediary negative.
- Union case:
- common name for thermoplastic miniature cases, used generically for this type of case.
- see Case well.
- Weeping glass:
- see Salting.
- Whole plate:
- see Plate sizes.
- African Americans: used for Afro-Americans, black people.
- Aged persons: used for elderly, senior citizens.
- Couples: used for mixed gender couples of unknown relationship as well as husbands and wives.
- Fathers & children
- Indians of North America
- Miners: see also Gold mines and Mining.
- Mothers & children
- Pioneers -- California
- Racially mixed children
- Soldiers: used for men or boys in uniform. Most are Civil War soldiers.
- University of California (1868-1952) -- Faculty.
- Young adults
- Buildings: see also Commercial buildings, Hotels, Churches, Dwellings, and
- Cabins: see also Buildings.
- Carriages & coaches: see also Carts & wagons.
- Carts & wagons: see also Carriages & coaches.
- Cities and towns
- Commercial buildings
- Diversion structures (Hydraulic engineering): used for flumes and other riverbed mining structures. See also Sluices.
- Gold mines and mining: see also Miners
- Lumber industry
- Mining districts: used for landscapes or town views, usually in the California gold country.
- Photographic studios
- Sluices: see also Diversion structures.
- Stagecoaches: see also Carriages & coaches.
Guide to the cased photographs and related images from The Bancroft Library pictorial collections, bulk ca. 1845-ca. 1870
Scope and Content Note
Cased photographs selected from the collections of the California History Section of the California State Library
Scope and Content Note