by Keith Holmes
Photographic imagery on clay is familiar to most people through the decal process. Think of Elvis on a plate or Dad's face on a mug, and you'll get an idea how the commercial world uses decals for kischt and collectibles. Potters and ceramic artists have pushed the process in a more creative way, incorporating photographic elements into clay as decorative imagery or post-modern reference. But making decals is labor-intensive process that involves nasty chemicals and a working knowledge of photoshop and screen-printing. There are also certain limitations--the need for a smooth surface to place the decal, for example--that make it unsuitable for many on aesthetic grounds alone.
Title: Enesa 5 1/2" x 8 1/2"
by Keith Holmes 2001
There is a second option, however, for those who want to integrate photographic imagery into their ceramic work. Photographs, at their most basic, are pieces of paper covered with a light-sensitive emulsion. This emulsion can be bought separately and used to coat ceramic tiles or pots (and other materials, for that matter). There are three varieties available--I use Silver Print (by the Luminous Company). Once coated and dried, the tile is sensitized to light and can be printed upon like any standard photographic paper.
As with the decal process, printing with photo-emulsion has its negatives and positives. The primary benefit is the color and texture of the ceramic surface comes through the light areas of the photo-image. While the emulsion rides on the surface of the piece, the photograph seems to meld into the material; image and object become one. This gets away from the pasted-on look of many decals and allows the artist to work with the underlying texture and color of the piece. The photo-emulsion also renders extremely fine detail and allows you to easily scale the image up or down with the enlarger.
The biggest drawback to the process is durability. The emulsion doesn't stand up to the weather very well, and work must be displayed indoors (or covered with poly or epoxy resin for temporary outdoor applications). The process is also labor-intensive and requires darkroom access and familiarity with printing the black-and-white negative, which might be problematic for some. But anyone who can make a basic black-and-white print in the darkroom can do this process--or learn it in a couple of sessions.
The basic steps involved in printing photographic images on ceramic tile are outlined below. There isn't much room here, so most of the tricks are described in more detail on the website. The author also welcomes e-mail inquires at: firstname.lastname@example.org.
Working With Photo-Emulsion On Fired Clay
Coating the tiles with photo-emulsion
1)--clean tiles with water and dry
2)--cover the glazed surface of the tile with two coats of polyuerathane (Brush is best but spray is ok). I also recommend coating the backside and edges of the tile with polyurethane spray to keep the body from absorbing photo-chemistry.
3)--Place a bottle of photo-emulsion (a gel at room temperature) into warm water for 10 or 15 minutes until emulsion has liquefied.
4)--In the darkroom, lay out the tiles on cardboard/prepare brush/turn out lights
5)--Turn on the safelight/pour out the emulsion into a glass or plastic container/brush on
6)--Let emulsion dry with fan and lights off; when tacky, apply thin second coat and let fully dry overnight in total darkness.
7)--If you want brushstrokes or curved edges use one coat and take more time on brushing the emulsion on. Dry overnight in total darkness.
8)--At this point, sensitized tiles may be placed in light-proof black plastic for limited storage (approx 1 week) before using.
Printing the tiles
1)--The biggest point here is to mention that the emulsion won't work properly if the temperature of the chemistry and rinse water is above 66F degrees. Keep ice and/or chilled water handy in the darkroom to cool down the chemistry as needed.
2)--Rapid fix is not recommended--use the dry-powder Kodak hardening fixer
3)--Chemistry as follows: 1:1 dektol/dilute fix for stop-bath/full-strength fix/hypo clear/water rinse/final wash--ALL BELOW 66F DEGREES!
4)--Print just like paper photos--run test prints to figure out exposure, etc. You will notice the image seems to come up pretty fast and won't develop much more after that. Don't leave in the developer for more than 2 minutes or it may go gray on you
5)--Rinse well after developing--at least 15 minutes with cold water--30 minutes are recommended
Safety considerations for this process are pretty standard--use a mask and gloves when applying the polyurethane; wear gloves when coating the bricks with emulsion, and wear disposable latex gloves when immersing tiles in the chemistry. Wash hands and don't breath too much fixer! Should be no problems for most, but those who are sensitive to photo-chemistry may need to take further precautions.
But there are difficulties and limitations with the Decals are made with ceramic pigments that are photo-silkscreened onto a special paper. After sealing up the top surface with a cover coat and releasing the paper
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