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It is also possible to print on glass using other photographic, printing,
or xerographic techniques. Aside from technical competence, the key to
success is using glass enamels or similar glass paints so that the image
becomes permanent.
Of these techniques, the simplest is probably the use of the screen-printing
process to achieve photographic detail. Both require either a black and
white rendering or a film positive (a photo developed using a positive
halftone film which converts the photo into dots). Transferring of the
positive to the screen is accomplished by one of two main methods.
- Direct screen
emulsion. In this process, the film positive is applied directly
to the mesh screen. To do this, a photosensitive emulsion is applied
to the screen, then a film positive is place beneath the coated screen.
By exposing the emulsion to a bright light, the pattern on the film
positive is tranferred to the screen.
- Indirect emulsion.
In this method, the image is first exposed to a film, then the film
is developed and applied to the screen. This approach is easier than
the direct method, but it requires the use of an oil-based medium, rather
than the water-based medium most frequently used with glass enamels.
There are a number
of companies which make direct and indirect screen emulsion supplies.
Among these are Ulano and Speedball.
In addition to screen-printing techniques, many conventional photographic
techniques can also be adapted to print on glass. The key adaptation centers
on the use of glass enamels as the pigment. In addition, there are many
non-kiln-fired processes (such as photo embossing, xerography, and engraving)
which produce an image and which can be adapted to glass.
The use of print-making techniques to print on glass was pioneered by
Harvey Littleton, the father of the studio glass movement. Glass can make
an excellent printing plate or surface to be printed on. Glass enamels
can be used as a pigment and fired onto the glass or (although they are
not as permanent) the printing can be accomplished with conventional sign
painter’s enamels and epoxy paints.
Copyright © 1999 - 2002 by M. Bradley Walker
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