Bromoil printing begins with a normally developed silver print. A non-hardening developer, such as amidol or Ethol LPD, is preferred for processing. Subsequent bleaching and tanning of the print removes the silver and results in selective hardening of the gelatin. In other words, the non-hardened areas of the print (the highlights) will absorb water and repel ink. The hardened parts of the print (shadows and mid-tones) will accept ink, resulting in a positive image resembling the original print. The advantages of bromoil are that (a) it allows a considerable degree of control over final image quality and (b) it is permanent.

The bleaching/tanning solution is made of distilled water (1000 ml), into which 70 ml of 10% solution copper sulphate, 70 ml of 10% solution potassium bromide, and 30 ml of 1% solution potassium dichromate is added. This solution will bleach out about a dozen 5x7 prints.

The ink used in bromoil printing is similar to lithographic ink. Hard ink is used initially, followed by soft ink, although the former alone will result in a lovely effect resembling etching. Brushes are specially-made of either hog, bear or fitch hair. A source for materials is provided at the end of this article.

The inking process involves first soaking the matrix (what the original print is called after bleaching and tanning) in water to induce the differential swelling of the gelatin. Test strips are used to determine optimal soaking times, starting with five minutes and continuing up to about 20 minutes. The test strips should be completely free of surface water before applying ink. The strip that accepts the ink most easily, with good buildup in the dark areas and clear highlights, will determine the proper soaking time.

The matrix is then soaked for the determined time and the surface water removed (using a damp chamois). The matrix is then placed upon a support and ink is applied. The inking process requires considerable practice to master the technique and involves lightly coating the surface, pushing the ink into the shadows and mid-tones and out of the highlights. The matrix may have to be re-soaked several times during the inking process, especially if resin-coated paper is used. The final print is allowed to dry for several days before matting and framing.

by Rita Carnes, Albuquerque, New Mexico (rita@indirect.com)