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Sep. 21st, 2006
Photo processes: Gum
Sep. 21st, 2006 07:32 amTo summarize a lot of history in a small space, at the beginning of the 20th century a group of photographers manifesto'd photography into a more painterly "art" style. One of the popular techniques for getting these kinds of images onto paper was gum bichromate printing. Here's an example of the style:
The Flatiron, 1904, printed 1909 - Edward Steichen
Another one by Steichen from 1908:
Silver-based film works by suspending silver halide particles in a transparent base (usually gelatin.) When exposed, the light causes silver ions to form from the halide and when the film is developed the ions are converted to a stable metal and the unexposed silver halide is washed away leaving silver where there was light and clear gelatin were there was none. Viola, a negative. The same process is used to create a silver print - light is focussed through the negative onto coated paper and the areas where the light comes through the negative - which were the areas where no light hit it - are illuminated on the paper creating a positive image.
Silver, platinum, palladium, iron can all be used in the same way - light-sensitive salts are exposed and the non-exposed areas washed away.
Gum printing is a bit different. A light-sensitive chemical is mixed with gum Arabic which causes the gum to harden with exposure to light. This sensitive gum is mixed with a pigment and coated onto paper. It's exposed and then instead of the unexposed chemical being washed out of the gelatin the unexposed gum is washed off of the paper leaving only the pigmented hardened gum in the exposed areas. A single exposure is used for a monochrome print, or the paper can be dried and coated with gum with a different color to create a multicolor print. A three or four-color combination can be used to create full-color prints. It can also be used over gelatin-based prints, as in this portrait of Steichen made by Stieglitz which uses gum over platinum:
It's a difficult, sensitive process that can also be used to create stunning color images like this one by Steven Livick.
I've always been interested in processes that take a photographic image and through hand work create not just an image but a unique object and gum printing, to me, is one of the most fascinating.
The Flatiron, 1904, printed 1909 - Edward Steichen
Another one by Steichen from 1908:
Silver-based film works by suspending silver halide particles in a transparent base (usually gelatin.) When exposed, the light causes silver ions to form from the halide and when the film is developed the ions are converted to a stable metal and the unexposed silver halide is washed away leaving silver where there was light and clear gelatin were there was none. Viola, a negative. The same process is used to create a silver print - light is focussed through the negative onto coated paper and the areas where the light comes through the negative - which were the areas where no light hit it - are illuminated on the paper creating a positive image.
Silver, platinum, palladium, iron can all be used in the same way - light-sensitive salts are exposed and the non-exposed areas washed away.
Gum printing is a bit different. A light-sensitive chemical is mixed with gum Arabic which causes the gum to harden with exposure to light. This sensitive gum is mixed with a pigment and coated onto paper. It's exposed and then instead of the unexposed chemical being washed out of the gelatin the unexposed gum is washed off of the paper leaving only the pigmented hardened gum in the exposed areas. A single exposure is used for a monochrome print, or the paper can be dried and coated with gum with a different color to create a multicolor print. A three or four-color combination can be used to create full-color prints. It can also be used over gelatin-based prints, as in this portrait of Steichen made by Stieglitz which uses gum over platinum:
It's a difficult, sensitive process that can also be used to create stunning color images like this one by Steven Livick.
I've always been interested in processes that take a photographic image and through hand work create not just an image but a unique object and gum printing, to me, is one of the most fascinating.
