Processed to "Museum Archival Standards"

[tim atherton]

"is the purpose of this thread to undermine and confuse the achievability of a silver gelatin print"

I'm not quitew sure what that phrase emans - it seems rather consfused in itself?

We know roughly how well a silver gelatin print will last if processed to the best standards being discussed here, and stored according to archival/conservation standards for RH, temperature, dark storage and storage materials etc

We also know that many silver gelatin prints in collections are suffering because of poor processing, poor storage over the years, problems with acidic substrates or airborn pollutants.

That is, the permanence a silver gelatin print is only as good as its paper substrate, processing and storage conditions. This has always been the case.

This is well documented in museum and conservation work and is nothing new.

But yes, properly made silver gelatin prints stored in ideal conditions will last a comparatively long time (Though even then, such prints don't "last for ever" and the older they become the more "fragile" they become as the ageing process accelerates despite all of the above).

Poorly processed and/or poorly stored silver-gelatin prints may only last a fraction of their potential longevity.

[tim atherton]

damn - sent before it spell checked

"is the purpose of this thread to undermine and confuse the achievability
of a silver gelatin print"



I'm not quite sure what that phrase means - it seems rather confused in
itself?



We know roughly how well a silver gelatin print will last if processed to
the best standards being discussed here, and stored according to
archival/conservation standards for RH, temperature, dark storage and
storage materials etc



We also know that many silver gelatin prints in collections are suffering
because of poor processing, poor storage over the years, problems with
acidic substrates or airborne pollutants.



That is, the permanence a silver gelatin print is only as good as its
paper substrate, processing and storage conditions. This has always been
the case.



This is well documented in museum and conservation work and is nothing
new.



But yes, properly made silver gelatin prints stored in ideal conditions
will last a comparatively long time (Though even then, such prints don't
"last for ever" and the older they become the more "fragile" they
become as the ageing process accelerates despite all of the above).



Poorly processed and/or poorly stored silver-gelatin prints may only last
a fraction of their potential longevity.

[Paul Butzi]

Even where excellent test data are available, as with what Wilhelm is doing, there are unresolved, and really unresolvable, questions about extrapolating results from artificial to real-world conditions.

Oren, I agree completely.

If I can change the subject somewhat in mid-thread, I'd like to ask another set of questions: do you think that there is any correlation between accelarated aging and real world longevity?

That is, suppose we just grant that getting a result of '150 years' on one of Wilhelm's tests doesn't mean that we can realistically be confident that we could make a statement like "90% of the prints will show no degradation in 150 years".

But if I look at one set of materials, and the results on the Wilhelm test are, say, 70 years, and another set of materials the results are 200+ years, should I feel pretty confident that the second set will last longer in virtually all situations?

Because in the end, you're going to make prints, even if the best you can do is a print that lasts 15 years. And in the end, it appears that there's no knowing what the real lifetime of the print will be in advance. So about all you can do after settling on the process that will give you the results you want is make sure you're using materials that give you the best odds.

I've long wondered why there were no data on gelatin silver papers, and I had just concluded that with Kodak and Ilford holding such a large share of the market, that the big players had established reputations for quality that could be counted upon. Now that Kodak is out of the game and Ilford is restructuring, it seems like it would be pretty easy for standards to slip and for smaller players with limited resources to sell products that might have longevity problems.

[Brian C. Miller]

Paul, if the product quality slips, then what would that affect, exactly?

If the quality of the paper base slipped, would that affect the print as it is made, or would it only be evident after 50 years? I suggest that the paper base would not slip in quality, as the paper is most likely manufactured at a paper mill, not by the photographic supply company. Paper itself is not going out of style.

If the quality of the emulsion slipped, I think that would surely show up during the making of the print. Something would stand out like a sore thumb during development, washing, or toning. I think it might have been Efke which had a bad batch of film within the last 12 months or so. Its kind of obvious when a problem develops with the emulsion.

The only time I have heard of problems with a paper was related by Bernhard J. Suess in Mastering Black-And-White Photography: From Camera to Darkroom. He was soaking his prints during the wash cycle, and the emulsion slid off the paper while he was testing a new brand. Now, that's a definite problem with archival processing. The emulsion needs to stay on the paper! :-)

[Jorge Gasteazoro]

But if I look at one set of materials, and the results on the Wilhelm test are, say, 70 years, and another set of materials the results are 200+ years, should I feel pretty confident that the second set will last longer in virtually all situations?

Scientifically you cant, all you can say is that in real life if the predominant contaminant is one similar to the one used for the tests, then the 200 year print is more like to last longer than the 70 years print, even if they dont reach their predicted longevity.

The fly in the ointment is that even in households we dont have just one kind of contaminant or oxidizer. There are some that are far more damaging and pernicious than hydrogen peroxide. This could in fact result in that while the 70 year old print degraded faster under hydrogen peroxide, in real life the 200 year print could degrade faster than the 70 year old one because it is more sensitive to other agents not present in the simulation.

[Richard Ide]

Good Evening

I have a copy (1973) of the "Society of Photographic Scientists and Engineers " Handbook; published by John Wiley and Sons. There are five pages on archival processing. If this is of interest let me know either way and I will see if I can post the article. I imagine I will have to get permission from J. Wiley. I could also give a precis if prefered.

Richard

[paulr]

"But if I look at one set of materials, and the results on the Wilhelm test are, say, 70 years, and another set of materials the results are 200+ years, should I feel pretty confident that the second set will last longer in virtually all situations?"

Not really. You have to look at the conditions the tests were designed to simulate. If the tests cover lightfastness, temperature and humidity fluctuations, and a decent range of the most common atmospheric pollutants, then they're probably pretty indicative of most situations. But there are allways odd conditions that can be exceptions.

A couple of examples:

I worked at a commercial lab many years ago. We got a complaint from a customer that all the Cibachrome display prints that he ordered were discoloring wildly, just a couple of months after they were made. No other customers had similar problems. It turns out the customer was the owner of a hair salon. The prints were hanging all over the salon walls. God only knows what nasty chemicals get used there day to day, getting sprayed and misted into the air. But we came to the conclusion that the ciba materials (normally pretty lightfast and pretty stable) were getting destroyed by at least one of these poisons. We reprinted the work and this time laminated it, and had no further complaints.

Another story is from Wilhelm's Preservation and Care of Color Photographs. It's a summary of a study done by the Art Institute of Chicago on work that was sent on a long travelling exhibition. They wanted to see how well work survived under travelling conditions, so they took multiple densitometer and colorimetric measurements before and after. They also made rigid demands on display lighting and temperature and humidity conditions at all the institutions on the tour. Some of the results were as suspected: in general silver prints did much better than c-prints. But there were surprises. Some prints degenerated much more than anyone had predicted. Among these was a Stieglitz platinum print, which developed a significant yellow stain. The study wasn't designed to figure out why this happened, but the assumption is that it had to do with huge temperature swings during transportation--like from sitting in crates out on the airport tarmac in direct sun. No one's archival testing simulates conditions like these.

[Mark Sawyer]

With all due apologies to those who study and follow the ANSI/Library of Congress standards, the sad truth is, for nine out of nine photographers selling work "processed to museum standards," what it means is "well, the guy at the framing store said this was 'museum-quality' matte board, or pretty close to it..."

Seven out of nine for professional conservators...

[Steven Barall]

Archival is a lot like love. It's a feeling...

[paulr]

Michael, I don't know. If you go to the wilhelm research site and download the book (free pdf file) you should be able to find the source of the information. Maybe it will point you toward someone involved in that study, or in conservation of that collection.