what happens with expired paper? i have a LOT of it

[thelazerviking]

my photo teacher gave me two 100' rolls of 42" kodak mural paper that's been sealed in their original boxes. teh expiration date is april 1988. what does this mean for me if i were to use it?

thanks

 

[Hertz van Rental]

Depends on how it's been stored.
Paper is usually not too bad and it's probably still useable - but not for anything special.
As film and paper get older two things happen - sensitivity drops (the film speed decreases if you like) and base level fog increases. Not usually too much of a problem with paper.
Best thing is to go into the darkroom, cut a bit off and process it. If it comes out white then it's OK. If it looks greyish then it could be fogged. Unroll a foot or so and do another test. If it's still fogged keep going till you get white.
Paper that has fogged on the outside layers (some chemical fumes can fog it) is often OK further in.
Use it for contact sheets and experimenting.

 

[thelazerviking]

cool thanks i think i was to use them to make big pictures that i can put up in public places outdoors and stuff...so if igets med up 't eelso ad

 

[thelazerviking]

oh by the way i wnat to know more about this chemical fogging?

 

[ann]

if it does have some fog you can add some benzotriazole to the developer to aid in reducing the fog. use about a .2% solution add about 15ml at a time to a liter of deverlop.keep adding until the fog disappears.

If there is serious fog, use the paper for making photograms or something else fun and not important.

 

[Hertz van Rental]

if it does have some fog you can add some benzotriazole to the developer to aid in reducing the fog. use about a .2% solution add about 15ml at a time to a liter of deverlop.keep adding until the fog disappears.

Benzotriazole is primarily a restrainer, that is it inhibits unexposed silver crystals from being developed. In fogged paper and film the crystals have been exposed so you cannot inhibit their development. Any reduction in fogging by increasing the chemical concentration is caused by it working as a bleach. At this point it will not only remove the fogging but some of the rest of the image as well. It's usefulness is therefore very limited and it's effect are certainly not enough to justify using more of it when you look at it's COSSH profile.
It is a skin sensitiser that can cause dermatological problems, it is mildly toxic and, as it does not biodegrade, it is a pollutant.


In silver photography the process depends upon electron release and ion migration. Photons being absorbed by silver crystals is the main way of promoting this behaviour but it means that there are other ways too.
Shorter wavelengths like x-rays and gamma rays will quite happily work the same and fog film and paper. So too will ß particles from radioactive sources.
There are also a number of chemicals which work as electron donors and so will fog film. These are often used in colour reversal processing to give the second 'exposure'. Some decomposing plastics can give off fumes that will fog film, and I believe formaldehyde vapour does it too. And some compounds containing sulphur can also cause problems.
As long as you store materials in approprite sealed containers and keep chemicals seperately stored this should not realy ever be a problem.

 

[mysteryscribe]

Back when I had a real darkroom, not a big ole cardboard box with a changing bag around the front, my biggest problem was remembering to put the lid on the box. I bet I printed a thousand sheets of light fogged paper. Never had any long enough to expire.