The other day I was clearing out a storage room and came across a box of photos that I had taken between about 1946 and 1952. Pictures mostly of my schooldays, family, and friends. All, of course, in glorious black-and-white as I had my own darkroom from the age of 12 on. But among them were three color prints, obviously of the same vintage and made by me. How did I manage that?
A fourth print, too awful to show anyone, explained all. That little reminder opened up memories of the time in 1951 when I messed around with a magical darkroom process that actually converted black-and-white photos into full color. And not by painting them. Here’s the story:
In 1949 the Eastman Kodak Company announced its new Flexichrome color process, which used dyes in a gelatin-relief matrix; a logical outgrowth of its magnificent dye-transfer process introduced a few years earlier and discontinued in 1994. This earlier process made prints from color transparencies such as Kodachrome and used three matrices, one for each of the primary colors. The results are still regarded as the finest color prints ever made.
Flexichrome, on the other hand, began with black-and-white images printed onto a single sheet of a special “relief stripping film” coated with a gelatin matrix. After processing in a special developer containing a tanning agent that hardens the darker portions of the gelatin coating, the image is bathed in hot water. This causes the gelatin that was not hardened, i.e. the lightest areas, to be washed away. What we now have is a bas-relief of mountains and valleys corresponding to the photographic image.
The film is then run through bleach, completely removing the visible photographic image. This is soon restored by bathing the film in black Flexichrome dye. Since the highlights are the valleys, they do not absorb much dye. The thicker areas, however, absorb dye in accordance with their thickness. The film is again subjected to hot water, loosening the emulsion from its base. Carefully, this is stripped off and transferred to a pure white paper backing, then dried.
The print is now ready for coloring.
A curious thing about Flexichrome dyes is that they replace each other. The last dye washes any earlier one right out of the gelatin. If you put, say, blue over a yellow image you do not get green, but only pure blue. So you begin coloring with broad strokes on the largest areas, overlapping into other areas. Only at the end must you be especially careful, and even then any errors are easily corrected. Excess dye is blotted away.
Back in its day, Flexichrome was an elegant solution to a problem that had long plagued professional photographers. Large color films were “slow,” requiring a lot of hot light and long exposures. This was even worse a few years earlier, when commercial studios used “one-shot” cameras producing three black-and-white negatives, each corresponding to a primary color. By shooting a single image on fast black-and-white film both time and money were saved. This image could then be colored any way desired, and any colors changed at will.
But soon after that professional color films such as Ektachrome were improved so much that the Flexichrome process no longer made sense, and it soon fell into oblivion. Today this curiosity has long been forgotten.
The first Flexichrome print that I made in my basement darkroom back in 1951 is the portrait of a lady near the bottom of this posting. This was included as an exposed but undeveloped film in the Flexichrome kit for the purpose of learning the process. I took it through all of the stages and then applied the colors. The one of a young lady’s face surrounded by black is my own doing, and the one of a handsome young man is actually my high school portrait, taken originally in black-and-white by a local studio.
Copyright © 2010 Earl Steinbicker
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Jack Crawford was the originator of the 'Flexichrome' process. He became an emplyee of Eastman Kodak Company and Kodak commercialized the process.
Posted by: Bob Nelson | August 18, 2010 at 12:44 AM