Test for Contrast on Old Paper?

Doc W · May 22, 2017

I am looking to perform some kind of standard test on developer and paper. As we all know, contrast can be affected by developer or paper that gets a little old. I have quite a few boxes of paper that all have slightly different levels of fog, but I don't want to chuck it just because of my frugal Scots background (grandfather from Glasgow).

Therefore I am thinking of a test that I could do at the beginning of a session, especially when I am revisiting an older print to make new copies. I keep pretty good notes on prints so I don't have to start from scratch each time. So how about this? I make a print with a step wedge on brand new paper with freshly mixed developer. The contrast range on this print will be the standard for this paper and this developer. When I use another box of paper, I can do the test and compare to the standard and this should give me a pretty good idea of the differences between the two so I can adjust accordingly.

Do any of you do anything like this? As I said, my main reason is simply economy. I don't want to discard paper just because it is a little old and grey, like most of us.

pentaxuser · May 22, 2017

Sounds good to me.

pentaxuser

tedr1 · May 22, 2017

This seems plausible, I think it would be important to eliminate uncontrolled variables so that the only variable is the paper, everything else has to be exactly the same. I have heard that in addition to fog and contrast the paper speed can also change.

Doc W · May 26, 2017

Thanks for the feedback!

Doremus Scudder · May 27, 2017

One thing to do with older paper is to check for fog. In total darkness if possible, cut a couple of strips from a sheet of paper. Develop, stop and fix one as you normally would, but just fix the other. Compare the two. If one is darker than the other, your paper is fogged. Depending on the severity of the fog, you can add benzotriazole to the developer to remove it. If the paper is too fogged to completely clear with BTAZ you can still bleach back the highlights with ferricyanide in some cases. Lightly-fogged paper can be fairly easily saved with one or both of these methods. Very fogged paper is ruined for most printing purposes.

As for contrast: Your test with a step wedge is good, as is the idea of making a swatch book of step-wedge prints as a benchmark. If I suspect my developer is dying, I'll often run a step-wedge strip to check it. It's amazing how often I'm wrong here...

Speed is not a problem: just make a test strip and find your best exposure time. It may be longer for older paper, but who cares.

Best,

Doremus

RalphLambrecht · May 27, 2017

Doc W said:
I am looking to perform some kind of standard test on developer and paper. As we all know, contrast can be affected by developer or paper that gets a little old. I have quite a few boxes of paper that all have slightly different levels of fog, but I don't want to chuck it just because of my frugal Scots background (grandfather from Glasgow).

Therefore I am thinking of a test that I could do at the beginning of a session, especially when I am revisiting an older print to make new copies. I keep pretty good notes on prints so I don't have to start from scratch each time. So how about this? I make a print with a step wedge on brand new paper with freshly mixed developer. The contrast range on this print will be the standard for this paper and this developer. When I use another box of paper, I can do the test and compare to the standard and this should give me a pretty good idea of the differences between the two so I can adjust accordingly.

Do any of you do anything like this? As I said, my main reason is simply economy. I don't want to discard paper just because it is a little old and grey, like most of us.

Contact print a Stouffer steptablet to determine contrast and adjust accordingly

JPJackson · May 28, 2017

RalphLambrecht said:
Contact print a Stouffer steptablet to determine contrast and adjust accordingly

+1

ic-racer · May 28, 2017

Your blacks likely won't change much, the loss of useful density range is from fog in the unexposed paper. Just process some strips of un-exposed expired paper and compare that density to fresh unexposed processed paper. You don't need a step wedge.

If you did use a step wedge, you are only interested in the exposure (or lack thereof) from the densest sections. So, bascially, you don't need any exposure on the paper.

Test for Contrast on Old Paper?

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