Print degredation

Discussion in 'Darkroom Developing and Printing' started by David Vincent-Jones, Jul 2, 2006.

  1. I have some paper B&W prints (20 x 24) made some 30 years ago that are
    showing signs of my sloppy processing in that parts of the image are now
    looking 'sepia like'.

    The change is not so bad that I feel in need of reprinting but I really do
    need to stop further degredation.

    Is simply refixing and a good wash sufficient to maintain status-quo or are
    more extreme measures needed.

    David Vincent-Jones, Jul 2, 2006
    1. Advertisements

  2. David Vincent-Jones

    Lew Guest

    Is the sepia in the high lights or in the shadows?
    Lew, Jul 2, 2006
    1. Advertisements

  3. Lew, thanks for the fast response;

    The highlights still, relatively, appear to be OK .. with some reasonable
    white detail for that reason the general appearance is not so bad. The
    blacks, of course, don't show the problem to any great extent.

    This is a paper not RC print.

    David Vincent-Jones, Jul 2, 2006
  4. David Vincent-Jones

    dan.c.quinn Guest

    For starters I'd take it as a straight forward matter. The sepia
    is silver sulfide. Thiosulfate will dissolve silver sulfide. So,
    in water then soak in a weak plain hypo, sodium thiosulfate bath.
    An ounce of the anhydrous or half again as much of the penta
    in a quart or liter of water may do. Agitate every few minute
    and allow plenty of time. If nothing is happening I'd pull
    after an hour. BUT the print may clear in seconds.
    I don't know, never tried it. Should be safe. Dan
    dan.c.quinn, Jul 2, 2006
  5. Thanks ; I will give it a try ...

    David Vincent-Jones, Jul 3, 2006
  6. A late answer. Its hard to know exactly what caused this.
    Yellow or brown stains are often from sulfiding of the
    silver caused by decomposition of thiosulfate left in the
    emulsion although it can also be caused by residual silver
    halide. When its halide it can appear in the clear areas
    giving the print an overall yellow or brownish color,
    perhaps a bit blotchy. Atmospheric polutants will affect the
    image silver causing staining of the image but not the clear
    areas. Sulfides from mounting or storage material can also
    cause yellow staining, often concentrated near the edges of
    the print. Yellow stains can also be caused by the developer
    but these usually show up during processing.
    The other cause of degradation is oxidation, usually from
    gasses in the atmosphere, but oxidants can also come from
    mounting materials. Silver oxide can be yellow or brown but
    it is often black or metallic looking. The oxides are very
    fine and can migrate through the gelatin causing "mirroring"
    at the surface and a slight border around dark areas.
    Once either process has occured there is not very that
    can be done about it.
    Sulfide stains can sometimes be removed by the use of a
    Permanganate bleach. For instance:

    Kodak S-6 Stain Remover

    Stock Solution A
    Potassium Permanganate 5.0 grams
    Water to make 1.0 liter
    Make sure all the Permanganate particles are fully dissolved

    Stock Solution B
    Cold Water 500.0 ml
    Sodium Chloride 75.0 grams
    Sulfuric Acid, concentrated 16.0 ml
    Water to make 1.0 liter

    Sulfuric acid produces great heat when dissolving. Add the
    acid to the water slowly with constant stirring. Mix this
    solution in a heat proof container.

    To use mix equal amounts of A and B. Mix just before use,
    the mixed solution does not last.

    Bleach the negative or print in this solution until the
    image is fullty bleached, about 3 or 4 minutes should be
    Then clear in a 1% solution of Sodium Bisulfite or
    Then rinse well and expose to strong light, preferably
    sunlight, and redevelop in a low sulfite developer like
    Dektol or D-72 1:2. Then wash thoroughly.

    There are other treatments but they have proved to
    result in non-permanent images.

    You can try refixing but after a couple of weeks of the
    original fixing the residual silver halides change into a
    form wich can no longer be made completely soluble by the

    I think it would be easier to reprint. If you do (or after
    this treatment) tone the print using Kodak Brown Toner. The
    toner will give substantial protection to the image for both
    sulfiding and oxidation. This should be routine for any
    display print (you can also use Gold toner if you want a
    cold tone print).
    Richard Knoppow, Jul 12, 2006
  7. I left out a part. If there is "mirroring" from oxidation
    you may be able to remove it with a mild silver bleach. The
    mirroring is from image silver which has been converted to
    Silver Oxide by some polutant, migrated to the surface, and
    been reduced back to metallic silver by other polutants.
    A good bleach for removing this (also works for dichroic
    fog) is a Rapid fixer, like Kodak Rapid Fixer with Hardener,
    at film strength, with the addition of 15 grams/liter of
    Citric Acid. This solution works slowly but will also bleach
    some of the image silver if not watched carefully. Once
    bleached the print should be treated in a sulfite wash aid
    and washed. The treatment will remove the mirroring but not
    restore the image. Keep in mind that some of the silver
    making up the image has been lost, there is no way to
    replace it.
    This treatment can probably be used in conjuction with
    the permanganate bleach I described in my first post. This
    should be done first and the bleach and redevelopment
    Richard Knoppow, Jul 12, 2006
  8. David Vincent-Jones

    John Guest

    How about washing in water that is high in sulfur ? Much of my family
    lives in the Owensboro, KY area and when we go for a visit I have to
    take bottled water as the sulfur content is high enough to cause my
    nose to burn.

    John S. Douglas
    Photographer & Webmaster -
    John, Jul 12, 2006
  9. Richard;

    Thanks for the very detailed feedback .. both replies.. they gave me some
    most useful information.

    As a result of selling a house in which I had been living for more than 30
    years I came across a ton of images that had been buried and forgotten ..
    some processed for commercial purposes in just too much of a hurry .. but a
    few that I now feel are well worth salvaging and giving greater prominence
    in my current (digital photographic) life.

    I have, at any rate, now at least refixed and thoroughly washed the
    offending images to prevent further degradation but honestly I think your
    ultimate solution of reprinting is probably the best answer to the problem.

    Thanks again;

    David Vincent-Jones, Jul 12, 2006
  10. Beyond my knowledge but it certainly sounds possible.
    Other sulfur compounds will certainly cause image
    degradation problems.
    Richard Knoppow, Jul 16, 2006
  11. Snipping...

    I left out a note about the salt. Common table salt often
    has Sodium Iodide in it as a dietary suppliment as well as
    fillers of various sorts to make it flow freely. I don't
    know for certain that the Iodide would be harmful, it would
    produce some Silver Iodide along with the Silver Chloride.
    In any case, Kosher salt appears to be reasonably chemically
    pure Sodium Chloride.
    Richard Knoppow, Jul 16, 2006
  12. David Vincent-Jones

    Lloyd Erlick Guest

    July 16, 2006, from Lloyd Erlick,

    I had a box of Kosher salt in my hand at the
    supermarket yesterday. It is not iodized, but
    lists "yellow prussiate of soda" as an
    anti-caking ingredient.

    Yellow prussiate of soda turns out to be
    sodium ferrocyanide.

    There is no indication of the quantity
    involved. I'm sure the archaic name is used
    to avoid printing the word cyanide on the

    Lloyd Erlick Portraits, Toronto.
    telephone: 416-686-0326
    Lloyd Erlick, Jul 17, 2006
  13. FWIW: Pottasium Iodide is in Crawley's High Definition Developer:
    pretty much Microdol with p. iodide. Maybe Crawley
    was just making up some Microdol, only had iodized salt
    on hand, and claimed the results were higher in definition?
    Yellow Prussiate is s. ferrOcyanide, photography
    normally uses ferrIcyanide - Red Prussiate.
    However ferro can be changed to ferri by oxidation.

    A little bit of cyanide won't hurt anyone. A handful
    of almonds may have more than a box of K salt.

    Cooking spinach in water with kosher salt makes the whole
    mess turn blue. The iron from the spinach
    combines with the ferrXcyanide to form prussian
    blue of Cyanotype fame.

    Kosher salt is made in the same way as table salt
    except the crystals are bigger. Good for prime
    rib and margaritas. And making meat kosher [blechh -
    if you like your steak rare; me I've got some
    Mongol blood in me: a bucket of blood in milk is
    the way to start the day]. Apparently kosher salt
    isn't kosher in itself.

    Without knowing a whole lot more, I'd vote for
    iodized salt over kosher salt.

    There are some real chemists in this group who
    can correct/add to the above, so take it with a
    pinch of your choice of salt.
    Nicholas O. Lindan, Jul 17, 2006
  14. That's still obsolete. Most stuff nowadays calls cyanide "nitrile"; thus
    instead of calling the plastic vinyl cyanide, they now call it
    acrylonitrile. New euphemisms for old. OTOH, it is very difficult to
    separate the CN from the FeCN, so the hazard would be small. I would not
    wish to eat the stuff, but it may not be a great hazard. I notice my sodium
    ferricyanide does not even have a poison label on it. Neither does my Kodak
    Rapid Selenium Toner.
    Jean-David Beyer, Jul 17, 2006
  15. David Vincent-Jones

    Lloyd Erlick Guest

    July 17, 2006, from Lloyd Erlick,

    Assuming you are not commenting on the
    Republican Party's chances next time ...

    Does your vote mean you would use common,
    iodized table salt in developers, rather than
    Kosher salt containing sodium ferrocyanide?

    Is it worth going to a chemical supplier and
    buying sodium chloride??

    Lloyd Erlick Portraits, Toronto.
    telephone: 416-686-0326
    Lloyd Erlick, Jul 17, 2006
  16. David Vincent-Jones

    Lloyd Erlick Guest

    July 17, 2006, from Lloyd Erlick,

    Me neither; but I resist drinking out of Lake
    Ontario, so obviously I'm a bit weird.

    Kosher means 'clean', in the sense of healthy
    (if you want to stay healthy, don't let God
    see you eating the Wrong Stuff ...) — so it's
    a bit weird there's something in it I'd
    rather not eat even if it's no prolem.

    Lloyd Erlick Portraits, Toronto.
    telephone: 416-686-0326
    Lloyd Erlick, Jul 17, 2006
  17. David Vincent-Jones

    Lloyd Erlick Guest

    As I was searching around for information on
    yellow prussiate of soda, I came across a
    conversation amongst a group of people who
    fired stuff in kilns. Glazes and such.
    Someone needed some salt, and ended up with
    Kosher salt, and ended up firing the yellow
    prussiate, and later was amazed to learn that
    cyanide was likely released in the process.

    Still, they were not harmed and considered it
    an oddity. So maybe the salt is safe to eat.
    It's bound to bad for your hearing, though...

    But I still don't know if it has any
    photographic cnsequences ...

    Lloyd Erlick Portraits, Toronto.
    telephone: 416-686-0326
    Lloyd Erlick, Jul 17, 2006
  18. David Vincent-Jones

    Andrew Price Guest

    But wasn't Prussian Blue something pretty mean, too?
    Andrew Price, Jul 17, 2006
  19. David Vincent-Jones

    Greg \_\ Guest

    That would really put the maker's in a pickle, to do so.
    Greg \_\, Jul 17, 2006
  20. I have to change my vote to No. ... but I would also
    vote No on Kosher salt.

    Pickling Salt seems to be the least additive prone NaCl
    commonly available.
    $4.50 / 100 gms? That's $45 for a 1 Kilo box of salt.
    Pay extra to leave stuff out?

    With knowing a little bit more:
    Ref. Anchell:

    Crawley's FX-1

    Metol 0.5 gm
    S. Sulfite, anhy 5.0
    S. Carbonate, anhy 3.0
    P. Iodide 5ml of 0.001% soln
    Water to make 1 l


    Metol 5.0 gm
    S. Sulfite 100.0
    S. Chloride 30.0
    Water to make 1 l

    Table salt is 0.008% p. iodide, so if
    I did my math right:

    Crawley 50 micrograms NaCl/l
    Microdol 2400

    Which says to me that the FX-1 formula as a justification
    for using iodized table salt is wrong - concentration is
    500 times higher in Microdol made with table salt.
    Nicholas O. Lindan, Jul 18, 2006
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.