The photographs are made by coating paper with a mixture of gum arabic, coloring pigment and light sensitive potassium dichromate. Gum, derived from the African acacia tree, acts as a colloidal (sponge-like) agent for holding the dicromate mixture in suspension with the pigments until the light hardening action takes place during exposure.

For color, I use natural pigments taken from the earth (Italian and German soils are favorites) or organic pigments from things local, like walnut and camellia hulls, or imported from afar, such as sandalwood, indigo and henna.

The prints are made by applying the liquid mixture indoors with a brush, and after drying, attaching a negative to the prepared surface. Exposure takes place either outside in sunlight or inside under a bank of UV lighting. The print is then developed out in pans of water and then hung on a line to dry. This process is typically repeated on another day using other pigments. Most finished images take a week or more to create. Most are printed over three to six times, resulting in a full scale print of beauty and permanence.

In the 19th century, what a photograph looked like, what it was made from, and how it was created was very much a personal, creative decision. By 1900, expediency would settle on silver gelatin as the standard of the industry and the dozens of other photographic methods developed in the first years of photography were abandoned.

The wide variety of alternative photographic processes has fascinated me for years and I have experimented with many of them. In the gum bichromate process, I find a method of making photographs that is flexible, somewhat forgiving, has excellent surface qualities, and a beautiful finish. After years of working in a darkroom making conventional black and white images, it’s a real pleasure to work in color under the sun.

---Alan Dehmer