Every year my children’s school has an auction to raise money and I always donate one of my images. A few years ago I decided to do something especially for the school. I had been working with photographic emulsion on tiles on and off for a few years, but had never hand-painted on top of the emulsion. Doing this kind of project, where I have a deadline, helps push me to try new things. I planned to donate the tiles to the school where they would be embedded in a wall, but before doing that, I scanned the tiles and made prints that could be sold at auction. It worked out for everyone.
Images can be put onto tiles in several ways. Decals are the easiest and can be fired so that they are permanent, but I have never been happy with the way decals look. They usually look too perfect, which doesn’t really appeal to me. Liquid emulsion can go on any surface and shows the brush strokes (a look I am very fond of ), but I needed to come up with a way to make the image and treatments permanent. If the emulsion is on an unprotected tile, the image rubs right off if anything hot touches it or easily scratches if someone rubs against it.
I seem to like doing difficult things. I made a lot of extra tiles so that I could test them—and I needed them all! I found that I could use chalks directly on the emulsion and that was fine. But when it came to putting layers of varnish to protect both the color and emulsion, that was a different story. After much trial and error, my final method was to spray several coats of fixative to protect the chalk from the varnish, then coat the tiles with several layers of varnish for final protection. The tiles are now up at the school and several prints were bought as well. Best of all, I now know how to do this again.
If you are interested in trying a project like this, two companies still are making photographic emulsions: Rockland Colloid Liquid Light and Rollei Black Magic Photo Gelatine. There is also a new product (that I have not used yet) called PYROFOTO that is produced by Rockland. The kit consists of permanent majolica glazes, and can be used indoors and outdoors in wet and dry conditions without fading, as well asforfoodservice.Youalsocanmake your own emulsion at home in a blender or use decals to transfer images. There are so many possibilities that you just need to try things out and see what is best for you.
Liquid emulsion products are complete in one bottle and are silver- based sensitizers for applying to any surface, exposing by enlarger, and processing with conventional darkroom print chemistry. However, you will need to pre-coat your tile with either polyurethane (non- yellowing) or a gelatin/hardener mixture. A one-pint bottle of emulsion covers approximately 16 square feet. The finished print can be hand-colored or toned like any photographic print on commercial paper.
Preparing your tiles
There are several ways to prepare tiles. You need to experiment and see which works best for you.
1. Polyurethane should be sprayed at least twice onto the tile, letting it dry between each coating.Let the tile dry over night before coating with emulsion. Make sure to get a non-yellowing product (likely at an art supply store).
2. Buying gelatin flakes from one of the sources listed at the end of this article. Mix as follows:
• Hot distilled water: 750ml
• Gelatin: 5 grams
• 2% chrome alum solution: 20ml*
• Distilled water to make: 1 liter
Follow the same directions as above (three coats with drying between, and then a 24-hour dry time before coating with emulsion).
3. Knox Unf lavored Gelatin** can be bought in the grocery store. Dissolve one packet (three or four packets to a box) in one cup of boiling water. Cool the solution until lukewarm and then pour or brush onto your tile. Dry with a cool hairdryer and put on another coat. Repeat for a total of three coats. Then let dry overnight before coating with emulsion.
Preparing your emulsion
At room temperature, “liquid” emulsion is, in fact, a solid gel. It needs to be warmed up before it can be used or it is difficult to spread the emulsion and it will flake off in the developer. While there are a number a ways to liquefy emulsion, a few general rules apply to all of these methods.
1. First, use containers and tools made only of plastic, rubber, or glass. Metals, such as steel or brass, may contaminate the emulsion.
2. Second, ensure that both the temperature and the humidity in your darkroom are moderate to minimize drying time.
3. Liquid emulsion is just as sensitive to light as fiber-based photographic papers. However, the emulsion tends to be out longer than papers because of the coating and drying time as well as the developing time. Do not open the emulsion bottle until the safelights have been lowered.
4. Emulsion melts at 110°F and it takes approximately 45 minutes to liquefy a full bottle. If you overheat it, the emulsion burns and looks fogged. You can use smaller bottles to heat the emulsion instead of heating the large bottle.
5. I use a double-boiler method for heating so that I don’t burn the bottom of the bottle. I have a pot of water on a hot plate with a Pyrex measuring cup filled with water and the liquid emulsion bottle inside the pot of water. This makes the bottle float up and not touch the bottom of the pot.
Coating the tiles
Some people like to pour on the emulsion; I use a bristle brush because I like the brush marks. I prefer two
light coats to one heavy one, drying in between. Again, this is a personal choice; there is no rule here. You can let your tiles air dry or use a cool hair dryer, but either way, keep the safelights low, or if air drying, do it in complete darkness.
Exposing and developing
I expose the tiles the same way I expose fiber paper, using a negative and enlarger. To run them through the chemicals, you need to be careful.
1. Make sure your chemicals are cool (70°F or cooler).
2. Do not put tiles on top of each other; they will scratch the emulsion off the one underneath. The emulsion is very soft at this point.
3. Follow the developing instructions of the emulsion that you buy.
Once the tiles are exposed, let them dry completely. If you want to stack them when you are done, put something between them.
Before you start painting the tiles, I suggest using workable fixative; you can buy it at any art supply store. I spray the tile with two coats of fixative and use soft pastel chalks. I can work them with my fingers, remove them, or re-apply them to make the colors brighter.
When you are done, you need to fix the chalks or they come off. The emulsion is also soft and subject to spills (in other words, not permanent). Spray the tiles with workable f ixative, let that dry, and then spray or paint over them with polyurethane—non- yellowing—either matte or glossy. You’re done!
Emulsion bubbles or peels during processing or washing: Poor adhesion caused by incorrect surface preparation (use shortstop or water wash before hardening fixer); lack of hardener in the fixer or inadequate fixing time.
Emulsion melts during processing or washing: If solutions are too warm,the surface of the emulsion can be smudged with a fingertip.
No image or weak image: Insufficient exposure; emulsion not sensitized with working developer.
Blacks not deep enough or streaked: Emulsion coated too thinly, or too freshfor maximum blacks. Sensitize with developer as described on previous pages.
Spots or blotches of brown, yellow, or purple: Used liquid fixer instead of powdered fixer; insufficient fixing time; not sufficient quantity of fixer to wash away unwanted salts in the emulsion; insufficient agitation; weak or stale fixer.
Image fades over time: insufficient washing.
* Chrome alum is a hardener that not everyone uses. I find it makes a better solution, but that is debatable. In any event, to make a 2% solution: mix 5 grams of chrome alum to 250ml of distilled water. If have something that will measure less, use it. You only need 20ml of this solution and you cannot save it once it is mixed.
** Knox is food-grade gelatin, not photo-grade, and may have some impurities. It is always better to buy the photo-grade gelatin, but in a pinch, Knox will work.
Freestyle Photographic Supplies: http://www.freestylephoto.biz
Rockland Colloid Corporation: http://www.rockaloid.com/products.html