Common Use Dates: 1864-1910
Alternate Names: Photo-Relief Printing, Relief Printing, Photoglyptic Printing, Woodbury’s Process, Photoglyptie, Woodburydruck, Permanent Photograph
Mistaken For: Carbon
Process Family(s): Photomechanical, Pigment, Paper or Glass Support, Gelatin Binder, Print or Positive Transparency
The Woodburytype was considered the most perfect photomechanical reproduction process of its day. It is based on the light sensitivity of the dichromated colloid combined with an intaglio printmaking process called the nature print in which a natural specimen was pressed into a lead plate which was then inked and printed. The Woodburytype impression was filled with pigmented gelatin which was then transferred to a paper support with a special press. It is the only photomechanical process that achieves the continuous tone found in true photographs and as a result can be difficult to distinguish from true photographs, particularly the carbon process.
As is typical of nineteenth century printmaking processes, there are many and varied published versions of the Woodburytype process. It was invented by Walter Bentley Woodbury and Joseph Wilson Swan (with some patent dispute as both patented nearly identical processes). To make a Woodburytype using the most widely practiced variation of the process, first a gelatin relief, or matrix, was made. A polished glass plate was coated with collodion (according to some sources) and then a mixture of gelatin, albumen, sugar, and a dichromate salt. Once set, this sensitized matrix layer was stripped off the glass and dried in a desiccator box. The layer was then contact printed under a photographic negative with ultraviolet (sun) light, causing the gelatin to harden in proportion to the amount of light received. Exposure time could range from five to 60 minutes. The gelatin layer was then washed in a hot water bath which dissolved the unhardened gelatin in the highlights and mid-tones. Finally it was dried in a desiccator box. The end result was a very thin and hard positive gelatin relief matrix about 1/2000th of an inch thick. Next the gelatin relief matrix was used to create a lead intaglio printing matrix. The gelatin matrix and a lead plate were inserted into a hydraulic press, which pressed the gelatin matrix into the lead plate. This created a lead matrix: a mold of variable depth that corresponded to the density of the image. To make the final print, warm, pigmented gelatin was poured into the lead matrix which was pressed against a sheet of receiving paper in a special Woodburytype press. The gelatin took five minutes to set inside the press. Usually the print was then submerged in a 3-5% solution of alum or chromium alum to further harden the gelatin. A surface varnish may have been applied to help protect the pigment ink layer as well as to achieve a glossy or matte surface sheen. Prints were then trimmed and mounted into books, magazines, or onto card mounts. Up to six lead printing plates could be made with the same gelatin relief; many printing shops had rotating tables that allowed the operator to simultaneously run six Woodburytype printing presses.
In the mid-1860s Woodburytypes began to appear in books, magazines, and special edition printings. By the late 1860’s, printing firms like Groupil in France and John Carbutt’s American Photo-Relief Printing Company in the Untied States started to mass produce Woodburytype prints and lantern slides. Meanwhile, Woodburytype carte-de-visite portraits heightened the public visibility of celebrities, politicians, and monarchs alike.
The process’s drawbacks eventually led to its disuse. The Woodburytype required a special press and ink and therefore could not be printed simultaneously with text and had to be pasted or tipped-in to publications and books. By the early 1890s, printers began to favor half-tone processes that were faster and could be combined with type in a printing press. Woodburytypes continued to appear in limited-run books and journals into the early 20th century. However, the finely grained collotype, which had 1/5 of the production price of the Woodburytype and could be printed with a traditional press, eventually displaced the Woodburytype. The last Woodburytype press was sold for scrap in 1928.