As restrainer, I use either potassium bromide or benzatriazole, but prefer the benzatriazole. I use only about 1/10th as much BZ as PB. If you mix a 1% solution of BZ and store it in PET plastic (no oxidation worries with either PB or BZ so any container is OK) it lasts forever. I have had no problems with long storage.
First, fotch, do this: For each package of paper cut off about one square inch of paper (of course, in total darkness: I do not use 'safe'lights). Then, mark each piece on the back with a felt marker in order to identify which package it represents. (Use a simple number system.) Then place half of each piece of paper under an ABSOLUTELY light tight item (for example, a dead flat bottom of an item like a tape dispenser that has felt at the bottom). (NOTE: the raised devices of a coin might allow light to creep in unless you hold the coin down FIRMLY throughout the exposure.) Expose the paper to full room light. Then process normally. If the unexposed part is white, or nearly so, you have struck gold. The paper is good with little modification. If it is medium grey, you must do more than merely process, which I will explain later. If the paper is totally black, that might be an insurmountable problem but one that could greatly be improved with what I say below.
Add about 30 - 50ml of the restrainer per liter of working strength paper developer. (IE, 10% PB or 1% BZ solutions).
The trick to working with age-fogged papers is to develop for as long as you can in order to achieve max black while not developing so long that your 'whites' get any darker than medium grey. Restrainers work only so far in helping to rectify age fog. The rest of the problem is solved with reducer, after the processing is complete.
After development and fixation, do the following to reduce density: first mix potassium ferricyanide (4ml per 250ml of water; I use volume to measure powders, not mass) into a separate container. That is your bleach and will keep indefinitely. Then shortly before you reduce: mix four parts of this bleach to one part of fresh film-strength fixer. This is your undiluted reducer and is a bit different dilution than Farmer's Reducer. Then mix this reducer with from 10 to 50 parts water to make your working strength reducer because if you do not, the reduction will take place too rapidly. You must experiment here and make sure to make your print a bit darker than normal so that the reduction in density will not leave you with a washed out print. Knowing just how much water to add will have to become known through trial and error at the beginning. However, the 4 + 1 ratio of fericyanide and fixer remains constant. Agitate continuously in the reducer and remove just BEFORE achieving desired reduction. It does not hurt to briefly dip the print into the original paper fixer after this reduction. Wash.
You will find that this ratio of Ferricyanide to fixer is best for PRIMARILY reducing the 'dirty' whites in order to make them sparkle, without unduly reducing the blacks. It is remarkable how badly age-fogged paper can be and still allow great prints to result with this method. (However, don't think that you will retain the 'right' to change contrast with variable contrast papers: you will either have a far less ability to do so or you will find that filtration matters not with age-fogged papers) You will become frustrated upon your first attempts and I strongly suggest that you experiment with tiny prints in order to not only waste little paper but to allow rapid experimentation to be easy. You WILL attain confidence but too many of you will still use large sheets of paper and end up totally dismayed. Work small until you really master this process. The mixed reducer will last for maybe one hour since the amount of fixer is kept minimal with my ratio. - David Lyga
Last edited by David Lyga; 04-10-2013 at 08:55 AM. Click to view previous post history.