I have moved from one city to another. My stock of printing paper was split between my car and the moving van. Because of the weather, both got hot.

I'm concerned that my paper fogged due to the heat. I don't want to print on bad paper and I don't want to throw away good paper.

Thus, I ask if there is a test to check paper for fogging other than subjective analysis of a print?

Thanks.

-- Paul Arnold

-- Paul Arnold (osprey@bmt.net), July 07, 1999

Answers

I would suggest to cut one sheet in halves. Process part #1 just like a normal print. Process part #2 equivalently, except that you don't develop it. Comparing the two (after drying) should reveal fogging. If you have got a reflection densitometer, this might help to make the test more objective.

Now for the limitations: I don't know whether the heat could also have had a sub-threshold effect, as with pre-exposure, or flashing. I guess you could only find that out by comparing a contact of a step tablet made on your paper with one made on a new batch of paper.

-- Thomas Wollstein (wollstein@compuserve.com), July 07, 1999.

If it is only slightly fogger, benzotriazole added to the developer will restrain the highlights and keep them clean.

I think the other repsone meant to say: Process one sheet normally. IE Develop, fix, wash and dry. Process a second sheet by fixing and washing only and drying.

Im not sure how much density is considered fogging. 0.10 is just detectable to the eye when compared to a fixed out sheet of paper.

-- Tony Brent (ajbrent@mich.com), July 07, 1999.

Yes, take two pieces, both unexposed. Develop and fix one, and just fix the other. If the developed piece is darker, the paper is badly fogged, and cannot give good whites.

Mild fogging could have a similar effect to flashing, and be undetectable by comparing two pieces of unexposed paper, one developed and the other not.

For that very low level of fogging, the only test I can think of is to buy some fresh paper and compare rsults, either subjectively or objectively with a densitometer.

But I would suggest that such a low level of fogging doesn't matter. If you get good results from the paper, just use it. The only practical difference would be a slight reduction in contrast.

-- Alan Gibson (Alan.Gibson@technologist.com), July 09, 1999.