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Print Processing Chemicals

The total solution needed for an 8x10 inch development tray is about 500 ml.
The total solution needed for an 11x14 inch development tray is about 1 liter.

The capacities for the following chemicals will depend on whether you
are processing resin coated or fiber based prints. Resin coated paper
absorbs very little solution compared to fiber based paper.

These dilution rates and capacities may differ from those printed on the manufacturers
labels - use their dilution rates when in doubt.


Print Developer

Kodak Dektol or Ilford Multigrade Paper Developer (very similar products - the nice thing about the Ilford developer is that it comes as a liquid concentrate, while the Kodak product is only available in powdered form and requires mixing with very hot water (produces powdery dust during mixing and you can't use the solution until it cools to room temperature).
The easiest way to tell if your developer solution has been "exhausted", is to look at the color of the solution. When you first mix the developer with water, it will be a fairly clear "bright" solution. As the developer gets exhausted, it will begin to turn brown and dull (oxidation with the surrounding air). The overall print may look a little more "grainy" than it should and the white areas may be a little gray. Discard the developer and mix up fresh solution.

Also See - Foto-Info.com - (Black and White Chemistry Info)

  • Dilution Rate

    Ilford's Multigrade Paper Developer dilution rate is 1:9 - This means 1 part stock developer from the bottle to 9 parts water (50 ml developer & 450 ml water for an 8x10 tray or 100 ml developer & 900 ml water for an 11x14 tray).
    Kodak's Dektol dilution rate is 1:2 - This means 1 part stock developer to 2 parts water. (170 ml developer & 340 ml water for an 8x10 tray or 300 ml developer & 600 ml water for an 11x14 tray).

  • Capacity

    500 ml of developer in an 8x10 tray will process twenty to forty 8x10 prints.
    The solution will last 6 to 8 hours in an open, uncovered tray before the surrounding air oxidizes the solution.

Stop Bath

Used to neutralize the developer solution that remains on the print after you have picked it up with tongs from the development tray, and before you transfer it to your fixer tray. "Indicator" type stop bath can be used for both film and prints. Changes to purple under safelight illumination when the solution is exhausted (solution is no longer useful).

  • Dilution Rate

    Any brand of "indicator stop" - put 500 ml of water in an 8x10 inch tray and add about 5 ml of stop bath from the bottle. (solution should be a pale yellow color). The exact dilution rate is 1 part stop bath to 31 parts water, although slight variations in the concentration will suffice and will not harm your prints.

  • Capacity

    "Indicator stop bath" will be exhausted when the solution turns a purple or bluish color under safe light illumination. Discard and mix up fresh solution.
    You can typically process twenty to forty 8x10 prints in 500 ml of solution.

Fixer - (Also called Hypo)

Used to dissolve any remaining light sensitive silver from the processed print - hence fixing or stabilizing the print. A "hardening" fixer is generally recognized as the best for film to avoid later scratches, while a non-hardening fixer is generally used for print making. I use a non-hardening fixer for both film and print and it works well for me - I have not had any problem with scratched negatives. Its much cheaper and easier to work with one type of fixer.

  • Dilution Rate

    About 1:9 (1 part stock fixer to 9 parts of water )(50 ml of fixer & 450 ml of water for a 500ml solution). I would normally mix up a liter of working solution and just use 500 ml for my 8x10 tray or the full liter if using 11x14 trays (110 ml fixer & 890 ml water).

  • Capacity

    I would estimate that 500 ml of solution would process eighty to one hundred 8x10 resin coated prints. If you use fiber based paper, then you could process about 40 8x10 prints. When you are finished processing for the day, just pour your fixer into a plastic jug that you have labeled as "working fixer". This solution can be used over and over before it will become exhausted and will last about 6 months in a half-full stoppered bottle.

You can use fixer at the higher concentration of 1:4 (same as fixing film) for processing your prints if you want to. The only disadvantage is that fixer is costly and you will be using more at a 1:4 dilution. If fixing prints at 1:4, cut your paper fixing times in half - resin coated would now become 30 seconds and fiber based would be 60 seconds.

"Hypo Chek"

Allows testing of your "working" fixer to check for exhaustion. Use an "eye dropper" and drop 2 drops of "hypo chek" into your fixer tray - if a white precipitate forms - discard the fixer. Recheck occasionally - fixer lasts a long time before becoming exhausted.

"PermaWash" or "Hypo Clearing Agent"

Used to reduce washing times of prints - not generally needed if you are using resin coated papers, as the chemicals cannot soak into the paper as they would with fiber based papers. If you are short on fresh water, then this is worth looking into as the clearing agent will cut your washing times dramatically.

  • Dilution Rate

    About 1:4 (1 part stock Permawash or Hypo Clearing Agent to 4 parts of water)(100 ml of fixer & 400 ml of water for a 500ml solution). I would normally mix up a liter of working solution and just use 500 ml for my 8x10 tray or the full liter if using 11x14 trays (200 ml Permawash or Hypo Clearing Agent & 800 ml water).

If you plan to tone your finished prints, then you must use PermaWash or Hypo Clearing Agent - otherwise no matter how long you wash the print, there will always be residual fixer left in the paper, which will react with the toner and cause spotting or discoloration.

Silver Recovery

Rather than flushing used fixer down the drain and adding a lot of silver compounds to the environment, you have the option of purchasing silver recovery devices that you pour your used fixer into. These will effectively remove the silver from the fixer. The silver can then be recycled safely according to the package instructions.

Chemical "Life Span"

These are approximations, but the information should give you a rough idea. I store my chemical solutions in tightly stoppered plastic jugs and keep them in the darkroom. Darkroom temperature has an impact on chemical life, cooler temperature being better. The same goes for light, lack of light will slow the breakdown of the solutions.

When storing liquids in partially filled bottles, try and squeeze the bottle to eliminate as much air as possible before screwing the top back on. This will help to eliminate oxidation.

  • Stock solution Kodak Dektol (print developer)(after being mixed from powder) - about 4 to 6 months in full stoppered bottle.

  • Working solution Kodak Dektol - a few hours

Liquid developer should be fairly clear in color, if it appears brown and "milky", then pour it out.

  • Undiluted liquid print developer (such as Ilford's Multigrade Paper Developer) - a year or so in a full unopened bottle - half full bottle (air in contact with solution), about 3 months or less

  • Working solution developer (any brand) - 1 day or until exhausted by processing

  • Undiluted stop bath - years

  • Working solution stop bath - days or until exhausted by processing

  • Undiluted Fixer - years

  • Working solution Fixer - also years, or until exhausted by processing (check exhaustion with Kodaks "Hypo-Chek")

  • Stock solution Hypo Clearing Agent (after being mixed from powder) - many months - (same for Permawash)

  • Working solution Hypo Clearing Agent - a few days or until exhausted by processing the recommended number of prints - (same for Permawash)

Chemical Disposal

See Kodaks website for a comprehensive look at Waste Management

See Kodaks website for a comprehensive look at Silver Recovery



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