This acronym stands not for a formula, but a whole processing scheme. It gets its name thusly: “The optimization of using JD-4 for quick processing of holograms recorded on Slavich PFG-03M plates and film was made by Tung H. Jeong, Riley Aumiller, Raymond Ro, and Jeff Blyth; thus it is called the JARB processing regime.” From the Photographers’ Formulary instruction sheet for processing kit JD-4.
And it is a very clever processing regime, one I would have to admit to never having thought up myself. It solves a long-standing problem with some extremely soft gelatin holographic products, namely the Slavich PFG-03M and Sphere-S GEO-3. There must be something inherent in the manufacture of these 10 nanometer grain sized products that the gelatin binder is much softer than conventional holographic and photographic emulsions. The first recommended processing step from the Russian factory is a soak in a formaldehyde-based hardener, or the addition of formaldehyde to the developer, to harden the emulsion so that it doesn’t come off in the processing solutions. But who in their right minds, other than undertakers, want to be around this preservative, and how easy is it to come by?
If the goal of the hardener is to toughen up the emulsion so that it is less susceptible to falling apart, why not “set” the gelatin like everyone's favorite gelatin dessert, Jell-O (or equivalent in other parts of the world) by cooling it down? And that is where the genius of this approach comes in, a cold water immersion before development to toughen up the protein strands; cheaper, safer, and just as effective.
Another aspect of the processing so that the coating doesn’t leave the substrate is to continue the process at a lower than normal temperature. Coming from a photographic darkroom background, development of a photographic paper is so negligible at temperatures at less than 20C that there is a decided lack of shadow density. But after the cold water dunk the rest of the processing temperatures are at 18C (65F)! And not only does the emulsion stay on the plate, but it develops to quite nice densities! The developer recommended in the JARB scheme is JD-4, which is quite hyper-active. I have adopted this scheme for holograms I shoot on PFG-03M and GEO-3.
After development, the residual developer needs to be washed out, again in cold running water, even just as it comes out of the tap with no hot added to it. I deviate from the JARB directions by using a dichromate-based rehalogenating bleach for a couple of reasons. The dichromate destroys any sensitizing dyes, leaving a totally clear plate, and hardens the gelatin so that it is not as soft as out of the box. The bleaching redox reaction doesn’t seem to be affected by the cold water.
Another cold 5’ rinse to remove the bleach, 1’ in Kodak Photo-Flo or equivalent, and let dry. I never use hot air drying and only rarely put a squeegee to a hologram, as either of these actions could destroy the image.