How to test quality of old paper

Discussion in 'B&W: Film, Paper, Chemistry' started by jfdupuis, Feb 11, 2009.

  1. jfdupuis

    jfdupuis Member

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    Hi,

    At our club, we've just cleaned the mess around and collected a lot of papers left from former members. As there is a lot of very large size paper that would be nice to use, I wonder if there is a nice and quick way to test if the paper is still good.

    I tried to process unexposed paper to check paper fogging, but even if the paper doesn't show any sign of fog, I feel sometime like I'm not able to obtain good contrast out of a box.

    Jeff
     
  2. Ian Grant

    Ian Grant Subscriber

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    That's to be expected, as paper ages it very slowly loses contrast and speed, papers kept well last quite a time 5 or 6 years without any noticeable loss in quality. But past a certain point a drop in a grade is quite common and it may be harder to get a good D-max. Using a good contrast developer can usually help but you're never really going to get the same quality as using fresh paper.

    Papers all age differently so there's no magic cure, using a normal print dev at a twice the usual strength may help, plus adding a small amount of bromide or benzotriazole but a contrast dev like ID-14 is better.

    Ian
     
  3. Rich Ullsmith

    Rich Ullsmith Member

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    Hi, Jeff. If you take a strip from your box, chop it in two. One piece goes in developer and then fix; the other goes straight in fix. Compare with the lights on. This is the quickest way I have found to see if there is a problem, and how bad it is. It does not take into account threshold, but if you have a box that seems hopeful, I would try that next. Also, a sheet from the middle of the box has not necessarily been exposed to the same elements as the sheet on top.

    I have tried using restrainers to salvage old paper, and it comes down to a question of time versus money.

    In any event, I have found that even papers that are fogged beyond recognition for purposes of conventional processing will still give amazing results in lith development. I cringe to think of all the great papers I have thrown in the trash before discovering this!
     
  4. wogster

    wogster Member

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    A second test is to take an image that you know is easy to print and has a full range of tones from deep black to full white, and make a print, if your print looks good, then the paper is fine. Do an exposure test first, so you know your exposure time, as it may be longer then usual. If you can't get a decent print in 2-3 tries, then maybe try the Lith development suggestion above.
     
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    jfdupuis

    jfdupuis Member

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    Ok, I now understand that I should test for both fogging and contrast. For contrast testing, it would be nice if could make myself a negative that would look like a GND filter going from minimal to maximal negative density. Then, when test printing with this one, I could see all the gray scale that the paper could provide in a single test.
     
  6. nworth

    nworth Subscriber

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    The most obvious quality test is to make a print on paper that is known to be good and that is generally similar to the paper in question. Then make a print from the same negative on the old paper you are wondering about. Compare them. Look for fog and lack of contrast in the old paper. If the print is pretty much satisfactory, the paper is pretty much satisfactory. If it needs help, add some benzotriazole to the developer and make another print. If that doesn't work, you may be out of luck.
     
  7. jgjbowen

    jgjbowen Member

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    Get yourself a Stouffer Step Wedge.
     
  8. Mike Wilde

    Mike Wilde Member

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    I use old paper all the time. Anyone can make a nice print with new paper, but try to make a print sing when the stuff was dated to go in 1971, now that is fun.

    For fixed grade paper, contact print a step wedge with no neg in the stage, no filters in the optical path, lens stopped down to f/8, or f/11 etc. Get the exposure time to put the area between all black and all white somewhere in the middle of the image of the wedge. The number of steps between just not quite white and cant tell between steps that are black AFTER THE PAPER IS DRY lets you compute the contrast range. If using a 1/2 stop step wedge (usually 20 steps) then number of steps x 0.15 gives you the density range. If 1/3 stop (30 steps) x0.1 per step.

    The Kodak print projection scale, that gives the pie chart exposure test can even be pressed into service if you lack a formal linear step wedge; it will just use a bit more paper to test with it.

    Make notes of the height, lens aperture, time, etc, and where the steps appear. If you do the same test with modern paper, then you can figure out the paper spped by conparing where the first non white happens on the old paper, relative to the modern paper. Then you can proof on your ordinary stuff, and then step to the special paper and know what the best exposure is likely to be on the first exposure.

    The modern Ilford paper flyer has a little chart that shows how contrast range works relative to standard paper grades, and how filtration affects paper sped using the ilford filter series.

    If you think you have a variable contrast paper, then you can expose a whole range of filters, from max yellow to max magentra with a dichroic head, or acetate filters, and map the current response of the paper. I regularly do this with all VC papers I use. I use strips of paper about 1" by 5", and write on the back the exposure and filtration with a sharpie marker before processing, and then use the best exposure found to keep the image still on the scale with max yellow and then also max magenta test strips exposed and processed first. Develop all for the same time, hopefully at some standard temperauture you usually use.