Vitreography
Vitreography is a fine art printmaking technique that uses a 3⁄8-inch-thick (9.5 mm) float glass matrix instead of the traditional matrices of metal, wood or stone. A print created using the technique is called a vitreograph. Unlike a monotype, in which ink is painted onto a smooth glass plate and transferred to paper to produce a unique work, the vitreograph technique involves fixing the imagery in, or on, the glass plate. This allows the production of an edition of prints.
In addition to being relatively inexpensive, glass is chemically inert. It does not oxidize, nor does it change or interact with the composition of printing inks, especially yellows and whites, which can turn green or gray in contact with metal plates. According to Claire Van Vliet of Janus Press, intaglio vitreographs also have an advantage over metal in that the glass plate wipes cleanly in non-image areas, allowing bright white to coincide with “black that is velvety as a mezzotint” in the finished print.
Another advantage of vitreograph printmaking is its ability to withstand the pressure of the printing press with no discernible breakdown of the imagery, even after numerous runs. Printmaker Ken Kerslake wrote, “The glass plate will last indefinitely because, unlike [one of] copper or zinc, it will always return to its original configuration no matter how much pressure is applied.” A disadvantage to this is that unwanted lines or marks on the glass plate cannot be burnished out, as they can on a zinc or copper plate.
The transparency of the glass plate can be used to advantage, in that the plate may be placed over a preliminary drawing on paper to guide the artist in creating a drawing on the plate. This is done by placing the drawing face down on a light table (to allow for the reversal of the image in printing) and placing the vitreograph plate on top of it. Although glass is unaffected by compression in the printing press, it will break under tension. For that reason, vitreographs are always printed on an etching press, whose rigid bed will support the glass plate firmly. In addition, the press bed must be level and working conditions in the print shop immaculate. A particle of grit or dirt between press bed and the plate will create a tension point that will cause the glass to crack when pressure is applied.
American glass artist Harvey Littleton was a tenured professor of art at the University of Wisconsin in Madison when, in June 1974, he taught a workshop in cold-working techniques for glass artists. To cold-work glass is to shape or sculpt cold (as opposed to hot or molten) glass, or to produce texture or decoration on its surface. Cold-working is done by carving, grinding or engraving glass with various tools, or by selectively blasting it with abrasives. As a result of experimenting with various resists for sandblasting, Littleton became intrigued by the possibility of printmaking from glass. He asked his colleague at the University of Wisconsin, printmaker Warrington Colescott, to ink five of the sandblasted plates from the workshop and print them onto paper in his etching press. The first plate broke under pressure, but after making some adjustments to the press, the rest of the glass plates printed “like dreamboats,” Colescott said. Editions printed from the plates looked promising, and Littleton was awarded a research grant from the University of Wisconsin to continue the development of printing from glass.
...
Wikipedia