Fibre based paper storage in a freezer?

[Photo Engineer]

I think the purpose is to speed up development.

You may be right, but development of AgCl emulsions and AgCl/Br emulsions are pretty fast in their own right. It may have something to do with control of curve shape.

In any case, many papers do not contain these reducing agents at all.

I have found that papers with and without perform with good quality, but those with have worse keeping.

PE

 

[dancqu]

I think the purpose is to speed up development.

I don't think so. I've given this DI supercoat and or
emulsion matter some modest study. Some of the bits
and pieces follow. I've found no single comprehensive
reference.

Freestyle three years ago assured me that None of
their Graded papers had DI emulsions. They have since
added the EDU line and an Ultra does have a DI emulsion.
The Ultra is used for instructional purposes and it is stated
that with the usual developers time in the developer is
shortened. DI supercoats are mentioned.

I've checked a few papers and have seen None which
qualify for activation processing; all need a developer.

Steve Anchell suggests when making emulsions one
add some small amount of developer to adjust contrast.
Perhaps paper speed is also varied.

From posts just this thread; any amount of DI, supercoat
and or emulsion, will shorten life spans.

I've two quibbles with PE. First, I think migration rather
than diffusion more aptly describes movement of components
with in the emulsion. Second, for a more real world test, rather
than NaOH I'd suggest a 2% solution of nothing more than
sodium carbonate. The ph of the solution will be a little
above that found in the usual print developer.

Graded papers vs VC papers. From Freestyles statement
and the simpler construction of the Graded paper emulsion,
my bet is on Graded for longer lived papers.

Testing for longevity is unsure testing. How old was the
paper when the retailer got the paper and then how
long in inventory and how stored. Dan

 

[Photo Engineer]

Dan;

A few points here deserve comment.

I have no quibble with Steve Anchell, but I wonder if he has done as much emulsion making as I have and has done as much tinkering with curve shape. I wouldn't think of using a developing agent to tweak paper curve shape and that involves design of papers here at home and at EK both. There are more and better ways to do it. So, it may be and it may not be true, but my reaction (even with knowledge that EK papers contain the most reducing agent of all of them from my tests or the most powerful) is this "WHAT WERE THEY THINKING"???? You see, it seems to ruin the raw stock keeping. As an afterthought, it may be that the addition of these reducing agents has a different purpose according to the formulas of each manufacturer.

Second, I have tried using a carbonate solution vs an hydroxide solution and the carbonate does not give a positive test for some papers that the hydroxide test does give a positive test with. I'm not sure what this means, but I now distrust carbonate as a test solution. I have tried both. The hydroxide has always been more definite one way or another.

Third, diffusion vs migration is a rather vague distinction so it really doesn't matter what you call it as long as you understand that some of the chemistry in the emulsion on FB paper ends up in the paper itself, but none of the chemistry in the emulsion on RC support ends up in the paper. This changes the formulas, their keeping, and a number of other properties. I will discuss this thoroughly at my workshop with examples.

Finally, I have observed no graded paper test positive so far, but have detected the reducing agent in all VC papers tested. I find this interesting, but I have not tested enough papers yet to make a positive statement, just a generalization so far. This statement is only true for current products, not ones older than about 5+ years or so. I do have some on the shelf, but have not tested the really really old stuff.

PE

 

[Mark Layne]

PE
Interesting you say that EK papers contain more reducing agents. I have a friend who warned me about Polymax FA 'going off' relatively soon. I have some on the shelf but haven't checked it recently.
Back in 1988 I purchased some PAL Bromide and PAL Print Chlorobromide - both graded. They were being used by some well known photographers at the time and made beautiful prints. I suspect these were Efke papers but don't know for sure. I used some this past weekend with interesting results. The Bromide paper was as good as the day it was made.
The chlorobromide was fogged flat. I would have expected that as AZO is chloride and keeps for ever the chloro paper would have kept best.
Anyway I developed some of it in Kodalith Fineline ( have been unable to discover the difference between Fineline and RT) diluted 1+1+12.
The wet brown dries with some pink but has a full range of tones with NO base fog. On bleach an redevelop a fairly normal print can be had.

The main thing I learned is that old foggy Cd paper may make beautiful lith prints.
Mark

 

[Photo Engineer]

Mark;

You may want to apply the carbonate and the hydroxide test to some of your papers in the light to see what happens. I for one would be very interested.

Thanks for the informaiton.

PE

 

[Mark Layne]

Mark;

You may want to apply the carbonate and the hydroxide test to some of your papers in the light to see what happens. I for one would be very interested.

Thanks for the informaiton.

PE

Will do - you're really sending me to the bottom of the freezer
The Pal papers had been out for a few years.
Mark