The

Gum Bi-Chromate Process

The Gum Bi-chromate process is an old photographic process , usually produced on paper. It was only ever used on ceramics to make memorial images to be used on gravestones, most notably in France. Here the process used enamels onto fired porcelain discs.

I have developed the process so that it can be used on bisqued ceramic ware.

The process works by combining a glue element (gum) with a light sensitive element ( Potassium Dichromate or Bi-chromate) and mixing this with a colourant, in my case ceramic oxides and under glazes.

The mixture is painted onto the ceramic surface and allowed to dry. The piece is then exposed to light through a negative and the areas that receive more light are ‘fixed’ , while the areas that are blocked by the negative are unaffected. The piece is then washed in water where the un fixed areas are washed away to reveal a latent image.

These ceramic photographs can then be glazed, or hand-tinted with underglaze colours and refired. Rakued pieces are glazed with low temperature glazes in a Propane fired kiln.

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