Ceramic images through the photographic process

 Sally Howes
My Honours research followed on from an earlier body of work involving the printing of photographic images on to shards of crockery using a photographic emulsion. My final body of work entitled ‘Sojourners’ (A Chinese Altar) was made in honour of the Chinese miners and families who resided in Beechworth, Victoria, during the gold rush. The slip cast porcelain cups were modelled on a cup that belonged to my grandmother and represents my English heritage. Beechworth was also the reference for my studio body of work, ‘Maps of the Landscape’ referring to mapping the landscape from childhood memories. I used granite donated by the local mining company, UNIMIN Australia Ltd, in the clay body and in the glaze of the woodfired sculptural forms.

Printing an image on the inside of a cup

Preparation

[1] Make a strong solution of detergent in hot water and alternately scrub and rinse the ceramic surface using rubber gloves until the rinse water doesn’t bead up as it drains off the surface. Allow to dry.

[2] Prepare a subbing mixture of unflavoured gelatin and water. Sprinkle one level teaspoon (approx 3 grams) of gelatin on to the surface of one pint of cold water in a saucepan. Let stand for 15 minutes to swell the gelatin. Heat, stirring, until the gelatin is dissolved (45-56°C).

Paint the gelatin mixture on to the rinsed surface of the cup. Drain thoroughly and dry for at least one hour in a warm place with low humidity and circulating air.

Coating the Cups with Photographic Emulsion

(in the darkroom under a safe light)

At room temperature the emulsion is a solid gel. Before use, plunge bottle into a container of hot water and leave for approximately 5 minutes to turn the emulsion to liquid. It is important not to shake the bottle because bubbles may form. Pour the required amount of emulsion into a small plastic jug and add water at approximately 40°C at the ratio of 4 parts emulsion to 1 part water. NOTE: The recommended ratio for Fotospeed is 1 part emulsion to 4 parts water, but I found I needed a thicker mixture to adhere to the inside of the cups. Sit the small jug containing the emulsion into a larger jug of hot water to keep the emulsion fluid during application.

 

 

My research had shown that the image printed better on flat rather than curved surfaces. This was because the emulsion would not adhere to the curved surface. However, the clearest images with good contrast were printed on shards of saucers made from bone china. One of my lecturers, Greg Daly, suggested it was because an earthenware glaze was used which was softer, giving a better surface for the emulsion to adhere to.

The images that I found the most interesting were the ones I printed inside shards of cups. I liked the way the image distorted as it fell over the surface and I decided to take this further by making my own cups, and printing inside them. I enjoyed playing with the distortion. When you first look at the cup it appears to have a pattern inside. But it is not until you pick up the cup and bring it to your lips as to drink, that the image becomes clear and is no longer distorted. This result could not be accomplished using other techniques like decals or screenprinting.

I started testing earthenware glazes on tiles with eight different glazes. I then printed a photographic image across the tile to see which glaze worked the best. I was looking for a clear glaze that was not milky and an image that had good contrast and didn’t peel or lift off the surface during development.

Once I had decided on a glaze, I then tested the three different brands of photographic emulsion available at the time. I found Fotospeed LE30 gave me the best results.

 

 

[5] Developer

Place the cup into a container of developer deep enough to cover the cup. I used Kodak Dektol 1:3 at 17-18°C. Develop for 60 seconds.

NOTE: It is important that the temperature of the developer is kept under 20°C or the emulsion will start to lift off the surface or dissolve and go muddy.

Stop Bath Place the cup into a container of water deep enough to cover the cup. Stop for 30 seconds.

Fixer Place the cup into a container of fixer deep enough to cover the cup. I used Illford Fixer for Emulsion. Fix for 4 minutes.

Wash Place the cup on its side in a tray of cool, running water. Wash for a minimum of 20 minutes.

Drying Take the cups out of the water and hold upside down to drain. You can also hold the cup in front of a fan to speed up the drying.

NOTE: During the processing cycle while the emulsion is wet, the image is very fragile and can lift or wash off if not treated with care. Avoid pouring the developer etc on to the image because the pressure can cause the image to wash off. The plus side is, if you are not happy with the final print, it will wash off with hot water allowing you to recoat the cup and reprint the image.

As the image is not stable and will burn out in the firing process, it is only suitable for non functional work.

[3] Pour a small amount of emulsion into the cup then pour back into the jug while rotating the cup to cover the entire surface. Shake the cup, upside down and rotate in circles to drain the excess emulsion from the rim of the cup. Repeat the application process with ceramic shards or tiles which will be needed as test strips during the printing process. Allow the coated cups to dry in the darkroom with all lights off (very important), and a fan circulating the air. Leave them to dry for at least 2-3 hours. Place the cups in a drawer or cupboard in the darkroom as for photographic paper while printing.

[4] Exposing the image under the enlarger

Use a cup that hasn’t been coated as a test cup. Place the cup under the enlarger to see where the image will fall. Play with the placement by moving the cup around, cropping, enlarging, etc. When you have decided on the final image, mark the placement of the cup and note the height of the enlarger head so that the image may be repeated at a later stage. Move the cup away and make sure the image is in focus as it falls on the flat surface with the aid of a focus scope.
Print on a test tile or ceramic shard to determine the correct aperture and exposure time.

When the aperture and timing have been determined, place the test cup under the enlarger again to check the placement of the image. Turn the enlarger light off and replace with a coated cup from the drawer. Expose the cup.

 

Sally Howes graduated from the Australian National University, National Institute of the Arts, School of Art with a Bachelor of Arts (Visual) degree with Honours. Sally’s work was shown at her first solo exhibition at the Left Bank Gallery in Beechworth, Victoria in June 2002. The exhibition was sponsored by UNIMIN Australia Pty Ltd.