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  1. #21
    brian steinberger's Avatar
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    I understand that RC prints can "silver out" easily, but I don't understand why FB papers supposedly do not. What about all the many prints I've seen from before the 50s that have silvered out? There weren't any RC papers then, so how did this happen? Just bad processing?

  2. #22

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    Quote Originally Posted by RalphLambrecht View Post
    Ulrich

    You said, they are like new. This implies a comparison. How did you compare the print as it is now to the print it was then? Memory?
    Of cause not. But I have - as any of us, I suppose - criteria to judge a print, like contrast, shadow details, highlights, sharpness and the like. Compared to these criteria the prints are ok. The prints were at least 17 or 18 years on the wall. That's where the yellow tinge of the cardboard is from. They weren't behind glass though.
    Whether they alter over time doesn't matter. You are right in that. None of us can know but this applies to FB-prints either. What matters is that the prints do not degrade and to this I do not have any evidence for prints stored under usual household conditions. I have prints which were stored under the worst conditions you can think of. I will fetch them occasionally (if I can find them) and present the results here. May be this will give us some more insight.

    Ulrich

  3. #23
    tony lockerbie's Avatar
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    Bronzing and silvering out issues do plague RC papers. The problem seems to stem from the titanium dioxide layer used to brighten the whites. I have found that RC prints always do this when framed, photos in my cupboard are not affected.
    This would seem to hark back the OP regarding the photos stewing in their own juice so to speak. When I'm not photographing I'm a professional framer, and would concur regards the archival quality of timber frames. To be archival, you should use aluminium, a really good quality mat board, rag or Bainbridge Alphamat (which scavenges pollutants) should be a minimum. A good quality foamboard would suffice as a backing, sealed with framers tape.
    When I sell a B&W print, I always use fibre paper, never had a problem with this in the 30 or so years that I have been doing it.
    To get it all in perspective, I've seen some truly horrible techniques that were used on very old photos, but most seem to be ok!
    Oh, fibre paper will silver out if it's not fixed correctly.
    Tony

  4. #24

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    Quote Originally Posted by Ulrich Drolshagen View Post
    I have prints which were stored under the worst conditions you can think of. I will fetch them occasionally (if I can find them) and present the results here. May be this will give us some more insight.
    A special incarnation of Murphy's law: Something never used in decades will be needed as soon it has made its way to the landfill.
    Unfortunately the pictures were thrown away in February as we cleaned out a very humid room in our cellar. I once had the habit to collect all test-prints in a box. This box has bee stored for years in the attic, has survived a drowned cellar and the last few years was kept in a humid cellar room (95% rel. humidity during summers). As I have looked though the box last the only change I had noticed was that with some pictures the silver of the pictures had wandered a little over the edge of the printed area of the paper. Too bad that I can not show it anymore.

    Ulrich

  5. #25
    RalphLambrecht's Avatar
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    Quote Originally Posted by Ulrich Drolshagen View Post
    Of cause not. But I have - as any of us, I suppose - criteria to judge a print, like contrast, shadow details, highlights, sharpness and the like. Compared to these criteria the prints are ok. The prints were at least 17 or 18 years on the wall.
    Sorry Ulrich, but that is a comparison by memory, isn't it? I have my doubts about that. A more reliable test would be two identical prints, one mounted and displayed, the other unmounted and in a dark box. But, even then, who says the print in the box did not fade over time. Only a densitometer reading might be more reliable, but I'm not aware of any long-time studies, so, we are left with subjective judgements. I started an experiment to test the effectiveness of Sistan and toning in 2001, unfortunately, I was dumb enough not to take densitometer readings either.

    Obvious staining is easy to detect, but the absense of color changes does not mean that the print has not changed. Slight fading over time is hard to detect. Of course, one could argue that if it can't be detected, then it is not a problem. However, it could be an early warning sign that more trouble is on its way.

    I'm not willing to make a statement about print stability, just because I don't see a change, without a comparison print.
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

  6. #26
    Nicholas Lindan's Avatar
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    Quote Originally Posted by tony lockerbie View Post
    RC prints always do this when framed ... stewing in their own juice so to speak
    Exposing RC prints to bright light is also suspected in RC bronzing/silvering. I don't know what the results are for unframed exhibited prints.

    The best guide to the future is the past - by this criteria RC paper can't be considered archival. I use it "For Novelty Purposes Only", and don't loose any sleep over its properties.
    DARKROOM AUTOMATION
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    http://www.darkroomautomation.com/da-main.htm

  7. #27
    RalphLambrecht's Avatar
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    Quote Originally Posted by brian steinberger View Post
    I understand that RC prints can "silver out" easily, but I don't understand why FB papers supposedly do not. What about all the many prints I've seen from before the 50s that have silvered out? There weren't any RC papers then, so how did this happen? Just bad processing?
    I explained that in an earlier post. Silver ions can escape into the paper fibers but cannot penetrate the PE layer in RC prints, and consequently, accumulate at the surface to metallic silver. I have never seen 'silvering' in FB prints only in RC. Like to see an example if possible. I've often seen sulfide staining, and residual silver stains, both yellow, but never 'silvering' in FB. Sistan was developed to prevent this from happening in RC.
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

  8. #28
    RalphLambrecht's Avatar
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    Quote Originally Posted by tony lockerbie View Post
    Bronzing and silvering out issues do plague RC papers. The problem seems to stem from the titanium dioxide layer used to brighten the whites.
    That's what I've read too but don't understand. The titanium oxide and the silver emulsion are separated by a PE layer. How can they affect each other?

    Quote Originally Posted by tony lockerbie View Post
    I have found that RC prints always do this when framed, photos in my cupboard are not affected.
    That makes sense, the production of silver ions needs light, humidity and temperature.

    Quote Originally Posted by tony lockerbie View Post
    Oh, fibre paper will silver out if it's not fixed correctly.
    That is something different. Silvering happens at the boundaries of highlights and silver-rich areas, shadows. Not properly fixed prints suffer from staining highlights, mostly turning brown or fading.

    Again, I have never seen silvering in FB prints, but I'm not saying that it isn't possible. Just haven't seen it yet.
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

  9. #29
    RalphLambrecht's Avatar
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    Quote Originally Posted by Nicholas Lindan View Post
    The best guide to the future is the past - by this criteria RC paper can't be considered archival. I use it "For Novelty Purposes Only", and don't loose any sleep over its properties.
    Wise choice. I have adopted the same procedure for my prints.
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

  10. #30
    Photo Engineer's Avatar
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    Read the article by Ctein. The bronzing of RC images, according to his tests, comes from overwashing. Most prints on FB are slightly underwashed and retain a bit of sulfur which "tones" the image and protects it.

    This was apparently confirmed by others running similar tests. Sistan takes advantage of this by adding a bit of sulfur to the coating to prevent bronzing.

    PE

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