Metamorphosis Art Gallery

Stephen E. Strom
Photographer
Gum Bichromate Prints

The gum bichromate process dates back to the mid-19th century when it was discovered that gum Arabic (an organic colloid), when combined with the chemical ammonium dichromate, becomes light sensitive. Exposure of the gum-dicromate mixture to light causes the gum to harden in proportion to the amount of light striking it. This principle is used to prepare an emulsion by adding watercolor paint pigment to the gum-dicromate mixture, and applying the mixture to sized paper. An image is produced by exposing the coated, sized paper through a photographic negative, soaking the paper in water for several minutes, and washing away the unhardened gum-paint mixture in those areas which received little light (the dark parts of the photographic negative, or the light parts of the original scene). The process is repeated to produce a multi-layer images that can extend the tonal range of the print or, with appropriate choices of pigments, add color or texture. The gum print can also be manipulated during development when the print is wet. Photographers who made use of this process in the 19th and early 20th century exploited this possibility to create subtle, painterly effects.

The gum-bichromate prints by Stephen Strom typically comprise 6-10 separate layers and draw their strength from their rich tonality and extraordinary detail, unusual for the process. The use of heavy watercolor paper provides add to their textural quality.

Other image selections

Stephen Strom's Sonoita landscape photographs.
Stephen Strom's agave photographs.
Stephen Strom's flower photographs.

© 2004 Metamorphosis Art Gallery