Testing Outdated Paper
Is there an accepted way (other than the obvious) for testing outdated paper. I have 100 sheets of 10 year-old 16x20 Ilford Multigrade recently discovered in my darkroom --- also a 2% solution of benzotriazole available.
Thanks for any suggestions.
Just the obvious. I cut old paper into strips and put one strip into developer and one into fixer. After my normal developing time I stop and fix the developed strip and compare to the strip that is fixed only. I use red safe light for this procedure.
... and so what would this tell you?
when I've used old paper, I get an increased base+fog i.e. I cannot get any 'whites' only some low level grey
as if the paper were heavily pre-flashed. So, my question is, what to do with this information? Can you quantify
the B+F and use that to reduce exposer/developement?
Or is it more like: 'nope, ain't gonna use that because it's not worth the effort' ? [which was my eventual decision]
I'd make step wedge exposures at each grade filter on this paper and some fresh (control) paper and develop normally.
If you can't get white, then I'd make another set of step wedge exposures and develop with a restrainer... (on hand, I've got only Potassium Bromide so that's what I'd use)
Wow, I am so sloppy and unscientific when testing papers. I just print a negative that I kind of like which I know prints easily with a full range of tones. Generally I prefer to use a negative with more than the usual amount of contrast just so I can see how well the white and black print. If there's any fog, I throw in 2% Benzotriazole, a few millilitres at a time until the whites print cleanly. That's it. No quantifying level of fog; but I do keep note of how much Benzotriazole I've used for any particular paper and if the paper required more/less exposure than "usual" and more/less development.
I use Rick's method to test, its the easiest way to see if any fogging is apparent. Though I prefer to do it without any safelights on, just to remove another potential variable. If there is fog, and depending on how much, you can try restrainers to keep the whites. I use Potassium Bromide (KBr) as its pretty cheap. mix with water to create a 10% solution and add to a developer of your choice. Increase the concentration until you can get whites. Sometimes if the paper is to far gone this will not work even if you add a ton of KBr.
I've never used restrainer, but since I have a lot of outdated Galerie graded paper I've made notes from AA's "The Print" for future use. Here's what my notes say:
1. Prepare a 1% solution:
Dissolve 10g BTZ in 900cc of water, then add water to make one liter.
[B&H info says use water at 125F or higher due to difficulty in dissolving]
2. You might begin with 25cc of 1% BTZ per liter of stock Dektol. Use only enough to clear paper fog. Adding 50cc causes a noticeable shift toward blue. Adding 100cc will reduce paper speed by roughly 2/3-stop. Image contrast may also be increased somewhat (more so than KBr).
Potassium Bromide (KBr):
1. Prepare as a 10% solution:
Dissolve 100g KBr in 900cc of water, then add water to make one liter.
2. You might begin with 50cc of 10% KBr per liter of stock developer present in the working solution.
Check on the effect of the bromide and add more as needed for the desired effect.
Bromide sometimes adds a slightly greenish tone to the image, which can be overcome in most cases by selenium toning. With modern papers, bromide produces a warmer image. Paper speed will be reduced, requiring longer exposures – possibly longer emergence time as well, requiring lower than normal development factors.
Gee, that sounds pretty scientific to me... [empirical method, keeping notes...] thanks for the explanation
thanks also to silveror0 for the very detailed example, well worth trying...
Originally Posted by Molli
There's a good chance it'll be OK, Ilford reckon that their papers last at least 7 years if stored well, no extremes of heat/damp etc.
In my own experience it's unlikely there's any base fogging with 10 year old Multigrade, it may have slowed a little and have a very slight drop in contrast. To test for base fog just process a small piece for your normal dev time (unexposed) and compare to a piece unexposed/undeveloped but fixed.
If there's a slight drop in contrast you could use a more contrasty developer, like the Part B of Dr Beers, I used to use ID-14 an Ilford contrast developer.
I had a big clear out 3 years ago and tested quite a few boxes & rolls of old paper and only the warm-tone papers had deteriorated beyond being remotely useable, all the plain Bromide papers were fine some from the 1960's sloww, maybe dropped a grade none had base fog, the early Multigrade papers Kodak & Ilford had dropped contrast slightly but they were well over 10 years old.
So just give some a try.
I also use Rick's method. It works to show major fogging problems. But I suppose Molli's method is more accurate as it shows paper fog problems that are below the visual tone threshold. Like what happens when you flash paper to just below the point a tone is seen. I haven't seen visible fog on my old Gallerie. Maybe a slight loss of contrast.