B/W print turned mottled gold

Discussion in 'Darkroom Developing and Printing' started by Jim Stewart, Dec 11, 2007.

  1. Jim Stewart

    Jim Stewart Guest

    I'm in trouble.

    I sent my mother-in-law a really nice B/W
    print that I made and after about a year,
    the black areas turned an ugly mottled gold
    color.

    She wants a new print and I need to know
    what to do so that the problem doesn't happen
    again.

    I used Ilford chemistry and Mitsubishi Gekko
    paper.
     
    Jim Stewart, Dec 11, 2007
    #1
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  2. This is probably a problem with fixation or washing. Either the print
    is not adequately fixed (less likely; this would usually give some
    silvering instead of fading to a gold color) or was not adequately
    washed after it was fixed.

    The other possibility is that the print was mounted with materials that
    are not acid-free, which will cause fading which is visually similar to
    fading from improper washing.

    Revise your fixing and washing steps of your process so they are standard
    (don't use Ilford's fast-processing recommendations with non-Ilford papers)
    and ensure that the new print is archivally mounted.
     
    Thor Lancelot Simon, Dec 11, 2007
    #2
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  3. Gold? Perhaps more dull yellowish? Like spots of silver tarnish? If so,
    print is not adequately fixed/washed. Make sure you are using fresh fixer.
    And it certainly does not hurt to tone with highly diluted selenium mix.
     
    Lawrence Akutagawa, Dec 11, 2007
    #3
  4. This happens to RC paper - the reason for it is a
    matter of debate. Titanium dioxide in the paper
    reacting with UV light is one current suspect,
    sulfur from pollution or the mount material is
    another.

    The history of RC materials is one of
    problems followed by Kodak/Agfa/Ilford/xxx
    claiming 'we have fixed the problem'
    followed by either the reemergence of the
    old problem or the creation of an entirely
    new problem. I greet any explanation or
    solution with suspicion.

    Agfa RC was very prone to bronzing. I haven't seen
    any on Ilford RC but that may be a matter of luck/time.

    To keep it from happening again you might try using
    Ilford paper. Err on the safe side: use fresh fixer
    for 5 minutes, a hypo eliminator, wash for 1/2 hour.
    There are all sorts of fast processing methods but
    the old methods are known to not contribute to the
    problem.

    If the picture is in a frame then make sure you
    use acid free board for the mat and mount board -
    "4-ply 100% cotton museum board" is considered the
    safest: the core of the board should be pure white,
    not grey.
     
    Nicholas O. Lindan, Dec 11, 2007
    #4
  5. Jim Stewart

    Pieter Guest

    I don't know that RC has a history or a current problem like this, but I
    think the suggestions offered below are excellent. I immediately thought of
    incomplete fixing or incomplete washing, but mounting materials could also
    be a problem as suggested ny Nicholas below. I have never had a problem
    myself, but I frequently test fixer and fix with a timer then use an
    effective print washer. Hypo eliminator would remove any fixer left on the
    paper. I have only seen strange coloration and fading occur as the result
    of chemical contamination, usually in group darkroom settings.
     
    Pieter, Dec 11, 2007
    #5
  6. This is called silvering out and is common on very old
    photographs. It comes from oxidation of the silver image.
    The silver oxide is very finely devided and can migrate to
    the surface, where it can be again reduced to metallic
    silver by other polutants. Very finely devided silver
    (colloidal silver) is bright yellow, hense the gold color.
    The problem comes from oxidants in the atmosphere or
    from mounting materials. Sources of peroxides are plentiful,
    automobile exhaust, vapours from fresh paint, many other
    sources.
    Well fixed and washed prints are vulnerable. Actually,
    a very small amount of hypo left in the emulsion acts to
    protect the image by creating a layer of silver sulfide on
    the individual silver grains. However, a much better way of
    protecting the image is toning. The best toners for image
    protection are sulfiding toners, selenium toners, and gold
    toner. While it was found that Kodak Rapid Selenium Toner,
    in very high dilutions, was not effective for microfilm a
    stronger dilution _is_ effective for pictorial films and
    prints where some change in image color or density is
    acceptable. According to Dr. Douglas Nishimura, of the Image
    Permanence Institute of the Rochester Institute of
    Technology, a minimum of three minutes in a solution of 1:9
    KRST will protect the image. Another very good toner is
    Kodak Brown Toner, a polysulfide toner. Polysulfide tones
    all densities evenly so any amount of toning which results
    in a visible effect on the image will protect it. Gold
    toning is similar but is expensive so its not much used
    although its still the standard for microfilm.
    While inadequate fixing and washing can cause image
    degradation the effect is most often a brown or yellow
    staining. Lack of complete fixing causes overall staining
    because the remaining insoluble reaction products are
    distributed throughout the emulsion. Inadequate washing can
    result in an overall stain but often shows up more as an
    imagewise stain. While both stains can be removed the
    process can further damage the image and the resusults are
    not always permanent. Once an incompletely fixed image is
    allowed to age for a few weeks it can no longer be
    completely fixed by re-fixing because the reaction products
    continue to change in the emulsion, eventually becoming
    impossible to remove.
    Despite the problems with inadequate fixing and washing
    oxidation of the image is caused by external polution and
    well fixed and washed images are particularly vulnerable.
    About 15 years ago some RC papers had problems with
    image oxidation caused by peroxides being emmitted by the
    titanium dioxide used in the reflective layer. This problem
    was solved by adding peroxide scavengers to the reflective
    coating and emulsion. The scavengers are self-regenerating
    so they remain effective essentially for the life of the
    print. These same peroxides also attacked the plastic layer
    in which they are suspended causing it to crack and flake.
    This has not been a problem for RC for many years now.

    Silvering out can sometimes be removed by a mild silver
    bleach, a treatment similar to removing dichroic fog. The
    safest method is to treat the print is a bath of fresh rapid
    fixer to which is added citric acid in the amount of about
    15grams per liter. The print must be watched carefully
    because this treatment will also bleach out the image.

    However, the best solution for your problem is to make
    new prints and tone them as suggested above. The toning will
    protect the prints against even pretty severe oxidative
    attack.
     
    Richard Knoppow, Dec 12, 2007
    #6
  7. I should have stated this more clearly. Tone in KRST at
    a dilution no weaker than 1:9 for a time of not less than 3
    minutes. This should give protection to all parts of the
    print or negative. The problem with KRST is that it tends to
    tone the more dense areas of the image more quickly than the
    less dense parts. So, when toned according to the old
    recommendations, that is, in a 1:19 solution for a couple of
    minutes, as when combining KRST with a wash aid, the toning
    is not sufficient to protect the shadow areas of negatives
    or the highlight areas of prints. The high dilution method
    was first suggested because it did not significantly change
    the structure, density, or color of the image, important
    properties when toning microfilm but less important to
    pictorial film or prints. Toning according to the current
    recommendation _will_ result in some change to the image as
    will toning in KBT as suggested.
    Toning of pictorial materials is less critical than
    toning of microfilm so some restrictions which apply to the
    latter do not apply to the materials we mostly use.
    Again, gold toning is quite effective and does not cause
    much change to the image appearance but the toners tend to
    be expensive. Gold tends to generate a neutral to blue image
    and, for this reason, may be desirable for some prints. In
    general, the warmer toned the original image the more it
    change in appearance in any toner, becoming more yellow in
    sulfiding toners and more blue in gold toner.
    However, the color is dependant on many factors, so, for
    instance, microfilm does not become sepia colored in KBT but
    rather shifts toward blue.
     
    Richard Knoppow, Dec 12, 2007
    #7
  8. Having similar problems with early digital prints, we got into
    the habit of spraying them with a fixative designed for art work.

    Would this work?

    Geoff.
     
    Geoffrey S. Mendelson, Dec 12, 2007
    #8
  9. Jim Stewart

    jjs Guest

    Richard Knoppow wrote:
    [...]

    So very well expressed. Thank you for that, Richard.

    (I thought maybe the OP had The Mydas Touch.)
     
    jjs, Dec 12, 2007
    #9
  10. Jim Stewart

    Jim Stewart Guest

    Thanks to everybody, especially Richard and
    Nickolas. I *really* appreciate the details.

    I will be remaking the print with Ilford paper
    and toning as Richard described.

    Thanks again,
    -jim
     
    Jim Stewart, Dec 12, 2007
    #10
  11. At one time it was recommended that prints be coated
    with laquer, in fact, Kodak used to sell print laquer.
    However, although it may protect surfaces from contact with
    air this is not always effective since oxidizing material
    can reach the print through the support plus the coating
    makes it difficult if not impossible to treat the print
    should that become necessary.
    In the case of RC prints it was found that covering the
    prints caused a trapping of the gasses emitted by the
    reflective layer. This may no longer be the case for paper
    containing the scavengers and anti-oxidants but is still not
    recommended.
    Remember that the digital images are composed of dyes or
    pigments, not metallic silver. It may be that laquer would
    be suitable for color prints were the images are composed of
    dyes.
    The best protection for silver prints is to tone them.
    I did not mention in my other post the use of protective
    agents such as Agfa Sistan or Fuji Ag-Guard. The Agfa
    products is discontinued but may still be found and, AFAIK,
    Fuji does not sell Ag-Guard outside of Japan. They are not
    identical but both use substances which are supposed to
    stabilize the image without having any effect on its
    appearance. Fuji released some research on its product
    indicating it was effective but less so than toning. AFAIK,
    there was never any serious research done for Sistan
    although there is anecdotal evidence that it works. However,
    Sistan is sensitive to the amount left in the emulsion, too
    much results in staining.
     
    Richard Knoppow, Dec 12, 2007
    #11
  12. Jim Stewart

    darkroommike Guest

    I use a lot or Gekko RC and haven't seen this happen I do
    have a Polycontrast !!! contact sheet in hand that has
    started turning, I know for a fact it was inadequately fixed
    (old fixer) and washed. It was done where I work and the
    fixer was always left in the tray. Prints I do at home in
    my darkroom do not exhibit this issue since I process and
    wash one print at a time.
     
    darkroommike, Dec 23, 2007
    #12
  13. Jim Stewart

    ____ Guest

    By accounts I have reference to; that is personal conversations and
    experience some RC Papers from 1980's and before do have this issue.
    Especially machine printed RC silver based papers- Like Agfa RC's.


    Not fixing properly always can produce the issue: bronzing, the silver
    will migrate out to the surface if the fixer does not seal the top most
    silver molecules, having an airspace between paper surface and glass
    also seems rather important.

    Its probably also a result of how certain papers were once made with
    regard to the placement of the silver layer within the emulsion.
     
    ____, Jan 1, 2008
    #13
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