Ceramics and photography – a beginning

Many alternative photographic processes can be used to print on ceramics and clay. In this excerpt from Jill Enfield’s Guide to Photographic Alternative Processes, Jill shows us how to print Pyrofoto, Laser Transfers, Gum bichromates, Cyanotypes, Silkscreen PhotoEZ and Phototransfer onto different surfaces.

Writer / Jill Enfield
Photography / Jill Enfield, Glenn Rand, Robert Cone, Elisabet Moreto, Graciela Olio, Kit Anderson, Paul Dale, Rebecca Barefoot, Kate Missett, Mary Fretz

Throughout history, artists have been relying on others to help produce work. This is not anything new. I am a firm believer that the digital age helped in making this even more evident. The access to images through digital negatives has opened up new possibilities to all artists that are very exciting.

Ceramic and enamel on metal began in the 1750s with the appropriation of images from copperplate engraving. Then, in 1854, Leron de Marcarson, a Frenchman, filed a patent for a process of vitrified photography onto porcelain. Around 1860–70, when gelatin was being used in photography, photo-ceramics became popular. A layer of light-sensitive gelatin emulsion containing colored enamel glaze was coated onto ceramic pieces, exposed with a negative, washed in water for developing the image and fired. The primary use of this process was to put images on gravestones.

While I am not a ceramic artist, I discovered that many of the photographic processes can be used along with ceramics. I am in no way an expert, but this excerpt from Chapter 13 should get you started.

I have been working on and off with liquid emulsion on tiles for many years and I have always wanted to make them more permanent. I have read that some people have fired the emulsion and they have worked. I have never been able to find out how. I have made countless tests and the outcome is always the same – the silver burns off and I have been left with a plain tile. What a disappointment!

According to an article on printandclay.net (no longer active), Liquid Light does not have a sufficient metallic content to leave an image if fired. I have tried to use AG Plus, which has more silver in it, and I have also added silver, but to no avail. Apparently, silver fires out in oxidation, which means it disappears. (If anybody reading this has done this successfully, please let me know how!) Almost any other metal can work, such as platinum, palladium or gold. This may be a little expensive for the average photographer to experiment with, but it is possible to do.

When I heard there was a class at a pottery studio in Greenwich Village on photography and ceramics, I had to take it. By the way, I am horrible at hand building! But I decided I was there to try things out, so I did the best I could. Luckily I had a great teacher (Kate Missett, whose work is in the book and this article) and a lot of fun people in my class. I laughed a lot. I suggest that if you have never done any firing before, take a class.

Not everything photographic can be fired, but you can still use ceramic pieces to get great results. For example, instant film transfers, liquid emulsion and Lazertran decals can be used and then protected by several coats of varnish. They cannot be used on a floor, but they can certainly be used for decorative purposes.

The most common method seems to be with silkscreening techniques. Cyanotype can be fired. Its color changes from blue to reddish-brown or yellow, but it is permanent. Gum bichromate can also be fired, but instead of mixing watercolor pigments in with the gum, you use what are called mason stains. The printing is pretty much the same as if you were working on paper, you just have to learn what color the mason stains change to after they are fired. And while inkjet transfers do not work, using a laser printer with Waterslide Decals works well. Rockloid has a product called Pyrofoto that I was hoping would be similar to liquid emulsion. It is a great product, but it is more for high-contrast line drawings or images, not continuous tone.

Terms you need to know for this subject

Cone: A cone is a temperature measure. Potters buy them from their ceramic suppliers and place them in the kiln to determine the temperature. Each cone is made to melt at a specific temperature and is extremely precise – for example, 06 for earthenware, 10 for stoneware or porcelain, 018 for luster.
Undervitrified: This means the clay has not been fired to the maximum melting point of the silica in the clay body, so it remains more breakable than it should be. It is the same as underfired. It is especially important to fire tiles to their correct maturity or melting point as they often sustain heavy use. For example, they are often cleaned with various chemicals (like in a kitchen) that could cause later problems in the glaze, such as cracking or pitting.
Mason stains: These are commercial combinations of colors.
Oxide: These are pigments from the ground – there are only seven that are natural.
Slip: This is liquid clay that seals the clay.
Underglazes: These come as slips, pencils and pastels, which you glaze over. Amaco is one company that makes underglazes that are semi-moist; they have color pen sets.

Duncan is another company. Ceramic stains change color as they fire, but underglazes are like water colors: the colors stay as they look before and after firing.

When firing photographic processes, note that silver burns out at about 500°F; for gum, bisque fire to Cone 2; if whites don’t clear, try Cone 6; cyanotype should be bisque to Cone 6.

Materials needed for these processes are as follows:

• apron
• Ceramic pieces – along with pieces for testing!
• sponges
• sponge brushes.
• glazes: premixed work well, such as Amaco or Majolica underglaze. The word glaze implies the chemical contains silica and will form glass. Glazes are specially made chemical concoctions that sometimes include mason stains as a source of color. If you use any of these sources of color, normally you put a clear glaze over them to seal them.
• high-contrast negatives or photogram materials
• nitrile gloves
• laser printer (fro Decals)
• positive image (for Decals)
• trays
• glazed pieces. (for Decals)
• ceramic mixing bowls
• negatives or photogram materials
• pencils
• drafting tape
• 3M #811 Magic tape
• plate glass
• UV box or sunlight
• hair dryer with a cool setting
• cups and bowls
• plastic spoons
• graduates
• storage bottles
• eye droppers
• running water

Pyrofoto

This is a product put out by the same people that do the Tintype Parlor Kit and Liquid Light, as well as other photographic chemicals and kits. Pyrofoto is a good option for getting high-contrast images onto bisque or high-fired ceramic pieces. Check out their website rockaloid.com for fun ideas and a list of products. Some camera stores carry their products, but if you cannot find them in your area, order from them online. Pyrofoto can be mixed with any liquid ceramic glaze and applied to a ceramic piece that has already been glaze fired. A transparency is then placed on top of it and exposed to UV light for 2–15 minutes. Using a sponge, you wipe away the unexposed areas and fire the piece again.
Pretty cool!

The steps

Working in dim room light (40-watt bulb):

1. Mix an equal amount of Pyrofoto in with the color glaze (1:1). If you are using Amaco glaze, the Pyrofoto will dilute your color a bit. If you want a darker, more saturated color, try doing the process a couple of times, or add some mason stain to the glaze.
2. If the mixture is really thick, add a little water. Mix often.
3. Wash your ceramic piece with powdered laundry detergent or whiting and hot water. Rinse well and dry.
4. Brush a very thin coat of the mixture on your surface.
5. Dry with a cool hair dryer or fan.
6. Coat again, this time a little thicker.
7. Dry.
8. Coat again, using the same thickness as your second coat (three coats should be sufficient, but you can experiment).
9. Dry.
10. Place your negative or photogram material on top and either tape it down or put a piece of plate glass on top of it. You need a good contact, just like in all the other processes.
11. Expose to sunlight or in a UV box for 5–15 minutes. This depends on your negative, the color of the glaze, how many coats you brushed on and your light source. In other words, do a test!
12. After the exposure, put in a tray of cool tap water for a few minutes to soften the emulsion.
13. Use a damp sponge with cool water and wipe away the unexposed areas. The image will slowly start to appear.
14. This can take several minutes – don’t panic! Go slowly or you can damage your image.
15. Dry the piece with a cool hair dryer and repeat with other colors as wanted.
16. Fire when you are finished with the image and the glazes are completely dry.
17. Make sure you work with someone who knows how to fire. The type of glaze you used determines the firing temperature (fire to Cone 06–05).

Troubleshooting and tips

• If your image does not start to show, you overexposed.
• If your image washes off, then your exposure was too short.
• If your mixture was too thin and watery, your image will be faint no matter how long the exposure was. This might be something you want to work with, using faint images and darker ones as a shadow of each other.
• Use this product only on glazed ceramic or on glass; non-glazed surfaces like bisqueware will not develop evenly.

Laser transfer decals

There are many companies that make these decals. You need to be sure to get the proper decal for your printer, as well as making sure they’re the decals for ceramics and can be fired. The recommended decals at the time of this printing were from Beldecal, a company in Florida decalpaper.com (no longer active).

They work in the same way Lazertran works, but these can be fired, which renders them permanent. (Lazetran instructions are on their website as well as my book in Chapter 12.) I have also used Papilio Aqua Slide Decal paper, but I had a few issues with it. It is stiffer than the Beldecal and I kept breaking it. I put it to my advantage and started doing it on purpose. I had issues with air bubbles with all of them – you really have to be careful and make sure they are all out. Use a soft brush or a wet finger to work the bubbles over to the edge of the decal and out. The Papilio/Z Bake was applied to a dish that was bought in a store and already glazed. They have an outdoor life of about three years unless you put urethane on it, then it may last longer. These transfers are recommended for indoor viewing. Lazertran cannot be fired, but it can be put into the oven. Slowly bring the temperature up to 400°F.

The steps

1. Print your image onto the decal paper using a laser printer (not inkjet).
2. Always print at the highest quality.
3. Wait about 30 minutes to make sure the toner has dried.
4. Cut out your image the way you want it to be.
5. Place the decal face-up in a tray of water until the image starts to lift away from the backing.
6. Gently transfer the image face-up onto your ceramic surface.
7. Pat flat, being careful to work out (from the center outwards) any air bubbles from under the decal.
8. You can use more than one decal before you fire.
9. Re-fire the piece several cones lower than the melting temperature of the glaze.

Troubleshooting and tips

• If part of your image is out of focus then you probably had an air bubble.
• If the decal does not have a good contact with the piece, the image will be out of focus.
• If you have holes in your image then you had air bubbles between your image and the ceramic piece. They popped in firing and left holes.

Gum bichromate printing

This is basically the same as printing on paper. I am using the recipe that Kate Missett gave me, but feel free to experiment with amounts, just like when you are printing on paper. I found working on ceramics much more rewarding than on paper.

Chemicals needed

25 g ammonium or potassium dichromate
100 ml distilled water
gum arabic: thin to the consistency of cream with distilled water
powdered oxide, mason stains or under-glaze

Mix the ammonium/potassium dichromate with the distilled water and store in a brown bottle or jar.

Steps

1. In subdued light, mix one tablespoon of gum arabic and half a tablespoon of powdered oxide, mason stain or under-glaze.
2. Add one tablespoon of dichromate and stir well.
3. Mark with a pencil where your image will go. The pencil will fire off and will not be seen.
4. With a sponge brush, apply an even coat of emulsion to the ceramic surface. Coat first vertically, dab your brush onto newspaper to clean off a little and then coat another layer horizontally.
5. Dry the emulsion with a cool hair dryer.
6. Tape your negative down with the 3M #811 tape – it will not show.
7. Place this under a piece of plate glass (if it is flat). Otherwise, make sure you have a good contact using tape.
8. Gum is built up with layers just like on paper. The first colors will be faint.
9. Expose the image for 7–15 minutes under UV lights. Slightly faster in bright summer sun.
10. After exposure, remove the negative and place the clay into a tray of warm water for about 10 minutes to soften the emulsion.
11. Start gently agitating the tray.
12. You can help the developing along with a brush, just like you do with paper. A fan brush works very well, or rinse the image with a sprayer.
13. Make sure the clay is totally dry before you add another layer of emulsion.
14. Repeat mixing and applying the emulsion with each color, making sure the emulsion is dry and you have a good contact each time.
15. When you are done with your image, make sure it is totally dry.
16. Apply a glaze and fire to the correct temperature (this depends on the glaze you are using).

A beautiful example in my class was made with the following colors in this order:

1. presidium yellow
2. orange “encapsulated”
3. saddle brown.

Troubleshooting and tips

• If the emulsion feels gritty, you have too much pigment.
• If the emulsion is watery, you have too much dichromate.
• If the emulsion is too tacky, you have too much gum.
• If the emulsion is applied too thickly, the bottom won’t harden and the whole thing comes off.
• If the entire emulsion comes off, try thinning the gum mixture with water.
• If the emulsion bubbles off, you underexposed.
• If the image is out of focus, you did not have a good contact between your image and object.
• If your image does not clear, you overexposed.
• If you cannot see any color at all, you underexposed.
• If your emulsion has been put on the thick side, increase your exposure.

Dichromate egg mixture, as per Kit Anderson

Kit learned how to do this from Peter Charles Fredrick, who called it Fredrick Temperaprint. He uses egg – either whole, just yolk or whites – rather than gum arabic mixed in with the potassium dichromate and pigments. Pigments should be either oxides or underglazes.

CHEMICALS NEEDED:

Eggs: 100ml of liquid filtered egg
Distilled water: 100ml
Ammonium or potassium dichromate: 3 teaspoons

STEPS

1. It is best to use fresh eggs from free-range chickens as they will produce a stronger binder because of the rich, viscous yolks, but any eggs will work.
2. Filter the eggs through a tea strainer or cheesecloth to get rid of the stringy clots from the egg, or any other bits you don’t want, or you will have white blotches in your image area. Put the strained eggs aside.
3. Mix 100 ml of distilled water with two teaspoons of ammonium or potassium dichromate. Store it in a brown bottle. Once mixed, add another teaspoon and mix well again. At the point where no more crystals will dissolve, you have a “saturated state.” No matter how much you mix, the crystals will still be at the bottom. Put the top on and rinse the bottle to keep the outside clean.
4. In another container mix 100 ml of liquid filtered egg and 50 ml of saturated sensitizer solution. Only mix enough for each session as once you mix the egg in with the dichromate, it will only last a few hours. Make sure to mix this very well.

Kit suggested mixing up a smaller amount:
one egg to 25 ml of saturated solution.
If you want a strong color use 3:1 (color to liquid);
for medium color use 5:1;
for light color use 8:1.

Experiment with amounts and combinations, but remember that very dark colors will stop light from getting through and may stop the mixture from becoming insoluble.

Cyanotype

Any clay can be used with cyanotype, so it is natural to use it with firing. The only thing to keep in mind is that a lighter clay will show the image better. Other than that, there is no difference between printing on paper or clay. No sizing is needed. You can use the same toners to change the color, or leave it blue. Some people use the 1:1 proportion like on paper and others have used 2:1. Try both and see which works best for your images and ceramic piece. Firing will change the color as well, and this is when it helps to work with someone who knows what they are doing with a kiln. You can fire a piece and then do another cyanotype to add blue back into the image. To make multi-color images, you can choose to just work with cyanotype or you can combine cyanotype and gum, just like on paper. In other words, you can use cyanotype, fire the piece, use gum colors, fire, the blue will change. Your last step can be cyanotype that you can tone or keep blue, or you can repeat so that one cyanotype is reddish-brown from firing, one is a plum color from toning and the last one is blue.

Exposures are just like on paper – anywhere from ten minutes to an hour. On clay, the image needs to be much darker. You will need to check the exposure by eye – the shadow areas (darkest areas of your image, clear on your negative) should be a silvery, very dark blue-gray color. You can do a test – make an exposure on paper and double it on clay. Wash the clay with running water until the water runs clear (first the blue that was not exposed will wash out, then you need the yellow in the white areas to wash out). I had no trouble washing my piece, but if you do, next time coat with a layer of gum before coating with cyanotype. The gum asks like a sizing and will help keep the cyanotype from sinking into the clay so that you can wash it out easier.

CHEMICALS

Each should be mixed and kept in a separate brown bottle:

Chemical A: is the light-sensitive chemical
ferric ammonium citrate (green crystals): 25 g
distilled water: 100 ml

Chemical B: adds the color:
potassium ferricyanide (orange crystals): 15 g
distilled water: 100 ml

Glenn Rand sent these suggestions about firing:

• Low-fire oxidation will change the iron particles to red or red-brown.
• If you fire to Cone 019, you can hand-color parts of the image with overglaze enamels.
• Oxidation firings at higher temperatures produce similar colors in the red/red-brown range, but the color will go even darker.
• Glazes over the image might cause the image to disappear. The proper cyanotype is very thin and if the glaze absorbs iron, the image will disappear because the cyanotype is not sufficiently saturated with iron to penetrate most matte glazes.
• The color achieved through reduction firing is a deep brown. This method is recommended for porcelain or white clays only.
• Salt-glazing leaves a faint gray on a strong white background.
• Raku firing leaves a gray image if you air-dry and do not smoke the piece.
• Cyanotype does not adhere well to glazes, so do not glaze over areas that you want to cyanotype.

Silkscreen – PhotoEZ

There are also many other processes that you can do on clay. I tried PhotoEZ, which is similar to silkscreening on clay. However, I found it not so easy, but included it here for people that may want to try it. This is really for working with line art – no continuous tone images. PhotoEZ is a light-sensitive emulsion that is applied to a fine mesh nylon screen in order to make screen stencils. Like the other processes discussed thus far, it is sensitive to UV light and when exposed the emulsion changes into a tough coating. When a black-and-white, high-contrast image is exposed on top, the emulsion under the black areas remains watersoluble and washes off, creating an open mesh for paint to pass through. If you take care of your screen, you can keep using it over and over again. Make a test image before using a larger piece! Before it’s developed, PhotoEZ is heat- and light-sensitive. Unused PhotoEZ should be stored in a cool place in the black envelope it comes in. Some people store it in a refrigerator for a longer shelf life.

STEPS

1. Working in a dimly lit room, cut PhotoEZ to the size you want.
2. It comes with a protective layer that needs to be separated. The green sheet is PhotoEZ. The emulsion side is the shiny side.
3. Lay it, shiny side up, on top of a black piece of felt or paper. The emulsion is the shiny side.
4. Place the POSITIVE

   

   transparency or photogram material on top. If you have lettering, make sure the lettering looks backwards. In other words, if you want the image to read correctly, you need to flip the image before printing so it looks backwards. This way, when you place the transparency down, it will look correct.

5. Smooth the two layers together.
6. Lay glass on top and clip together, or put it inside the contact print frame.
7. Expose. If you are dong this at noon, in the sun, it should take about 1–2 minutes. If you are doing this with a UV box, it should take about 6–12 minutes.
8. If you are using a contact print frame with a hinge back, you can check your exposure. Once the image looks yellow-green, it is ready.
9. Place the PhotoEZ in a tray of water for about ten minutes, making sure the image is completely immersed.
10. Gently dab the emulsion side with a natural sea sponge or a soft paint brush to clear the image area.
11. Lay your screen between soft rags and gently pat dry.
12. Re-expose the screen to a light source for a minimum of ten minutes.
13. Let it dry completely with the shiny side up. If the emulsion touches another surface when it is wet, it will stick to that surface. You can re-soak the screen until it releases from what it is sticking to, although it may scratch.
14. Once it dries, it is no longer light-sensitive and can be saved and used again.

Troubleshooting

• If the image is on the stencil, but is not washing out enough:
  It is probably overexposed. Reduce your exposure time or the image might not be dense enough; go back and tweak your positive to give it more contrast.
• If there is not an image and the stencil is blue:
  Make sure the artwork is placed between the light source and PhotoEZ; or you may have left PhotoEZ out of its protective bag for too long – work in subdued light.
• If the stencil is washing away:
  The light source is not intense enough or you did not expose for long enough.
• If the image is fuzzy:
  You did not have a good contact.
• If the film is lifting off the mesh:
  You’ve underexposed, leaving the film too soft; try a longer exposure. Or you’ve washed too vigorously – use gentler spray.
• If the center is not washing out and the edges are washing out completely:
  The PhotoEZ is too close to the light source and is creating a hot spot in the center, but the edges are not getting an exposure.
• If paint is bleeding under the stencil:
  The paint is not thick enough – try using thicker paint. Or the stencil is not making a good enough contact, or getting enough light. Try moving the light further away or use more bulbs and less time.
• If the paint is not going through:
  Dried paint is clogging up the mesh or the paint is too thick.

Photo transfer

You can use laser or Xerox images (but not inkjet). Smaller images are easier to start with as notebook size may give you some issues with tearing. You can cut images smaller and then tile them together. This will print midtones, but high-contrast images work best.

Materials needed

These materials are slightly different than the other processes.

• Linseed oil
• mason stains
• plastic container with a lid
• gum arabic
• two containers of about one quart of water: one with plain water and one with a splash of gum
• soft, leather-hard, greenware clay (not fired, but somewhat dry)
• plastic spoons
• brayer
• glass covering a table.

STEPS

Mix the stains the night before:
Mix two parts stain to three parts oil (using the plastic teaspoons will make about 50 images). Mix for 15–20 minutes – it needs to be mixed well! Leave overnight. The consistency is similar to acrylic paint – not too watery but not to thick. The ink will dry and it forms a crust – you cannot add more oil and make it workable again.

When ready to work

1. Spread the gum on the glass.
2. Put the image in the middle of the gum, face-up.
3. Spread to coat the image with gum so that the ink will stick to the gum.
4. Wipe up the excess gum on the glass – too much gum makes a mess.
5. Stir the ink.
6. Spread the ink in a line on the glass. Use the brayer to spread the ink on the glass – one direction and then the other so the brayer has a lot of ink.
7. Ink the image in one direction so it does not roll up on the brayer.
8. Wash the image with water and gum by squeezing over the image with the sponge – do not brush on. Start blotting to wash the ink off the white areas.
9. Repeat inking two more times for a total of three times.

NOW: Ready to put on clay

1. Lift the paper up by the corner.
2. You only have one shot to place this down on the clay. Once you place the image down, work from the corners out.
3. Use clear water and a clean sponge to blot.
4. Leave in place for a minute.
5. Burnish the image when moist but not soaked. (You can use a plastic spoon).
6. Use circular light pressure motions and make sure you get every detail.
7. Lift the paper from the corner – you can check it and place it back down and reburnish if necessary.
8. You can layer with different colors – deep brown and terracotta look great!
9. Fire like earthenware – Cone 06.

Thank you very much Jill for sharing this chapter with us!

Jill Enfield is a New Yorker, working in the liquid emulsion, kallitype, pl/pd, writes books and teaches workshops.