A decade ago there was an intriguing article in PHOTO Techniques magazine entitled “Silver Mirror Printing and other Unusual Black and White Print Development Processes” (William Jolly, pp. 32-36, Jan/Feb 1999; also “Silver Mirror Printing Update,” p. 11, July/Aug 1999). The process looked fasci- nating. A freshly developed, but not yet fixed, black and white print is subjected to two mild photographic solutions, an activator and a stabilizer, in the darkroom and out under room light. The activator is a dilute potassium hydroxide; the stabilizer is an acetate buffered thiocyanate. Colors appear where there is white in the print: orange, brown, yellow, pink, purple, green and blue, as well as silver on normally monochrome black and white paper.
All of these colors are the result of the “Mie” effect. The first actual article explaining this effect was in Scientific American (Dominic Man-Kit Lam and Bryant W. Rossiter, “Chromoskedasic Painting,” pp. 80-85 and 136-7, Nov 1991). Lam discovered the process in 1980, but it wasn’t until 1989 that Rossiter explained how the Mie effect was responsible for the colors that appear and gave a name to the process. Rossiter’s choice of “chromoskedasic” is Greek for “color by light scattering.”
Very soon, another article appeared in View Camera magazine, by Alan Bean (“The Black and White Corner; Chromoskedasic Painting,” pp. 40-43, Sep/ Oct 1992). At the same time, Professor Jolly, a chemistry professor at the University of California, Berkeley, began extensive research into the whys and hows of “chromo.” Lam obviously inspired many.