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The
Photogravure Printing Process
What is a Photogravure?
A photogravure is a photographic image produced from an
engraving plate. The process is rarely used today due to the costs involved, but
it produces prints which have the subtlety of a photograph and the art quality
of a lithograph. In essence, the production of a photogravure consists of three
steps: taking the picture; producing a printing plate of the image; and printing
the image on paper.
The basic process, also called photogravure, was developed in
the 1850s. After taking a picture, a glass transparency is made from the
negative. Next, a copper engraving plate is dusted with grains of bitumen and
heated so that the bitumen becomes attached to the plate. A carbon print which
has been exposed beneath the transparency is then transferred to the plate. The
plate is then bathed in warm water which causes the unexposed gelatin of the
carbon print to be washed away, leaving the image in relief. Ferric chloride is
then applied to the plate and eats into the copper in proportion to the
highlights and shadows of the gelatin relief. The result is an etched copper
plate of the original photographic image.
The final step, printing, involves spreading ink evenly across the plate and then pressing the plate onto the paper. The combination of the chemical and mechanical process produces an image both warm and precise. A photogravure looks like a photograph but is a series of connected lines, rather than unconnected dots as in a photograph. The rich sepia ink and handmade paper used for the Curtis photogravures are the final elements in the production of the beautiful art prints of the North American Indian. Return to Edward S. Curtis Collections Source: The Curtis Collection www.curtis-collection.com
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