Archival aspects of negatives developed in pyro developers

[wlambert]

Does anyone know of information on the long-term archival aspects of negatives developed in pyro? Does the stain deteriorate? Does it lighten, darken, become denser, or break down chemically? Does the stain eventually have harmful effects on the silver, gelatin, or substrate of the negative? Use of pyro developrs was widespread in the late-19th and early-20th centuries, and I would think there would be studies of the present nature of these old negatives. I assume many of those were glass plate negatives so a different set of issues might apply. I am thinking of moving to Ilford FP4 Plus developed in Pyrocat-HD or Pyrocat-MC. Some of my negatives are going to an archive for long-term use so that's why I am wondering about the stability of negatives developed in pyro developers versus negatives developed in non-pyro (MQ or PQ) developers.

Thanks,
Wayne

 

[Photo Engineer]

"These dyes like all dyes change with time" is a quote from Kodak color data on each box of film and paper. It is a truism that dyes are less stable than silver. There are those that argue against my comments here, but the answer is "we don't know". No one (AFAIK) has ever done tests on pyro negatives. I'm sure that they fade, but by how much and at what rate IDK.

PE

 

[pgomena]

It's hard to tell from the historical record. Not all pyro negatives are or were made with staining formulations. I think PE has the crux of it.

Peter Gomena

 

[EASmithV]

This is exactly why I decided to stick with traditional developers.

 

[Photo Engineer]

It is also probably why no major film manufacturer makes a pyro type developer other perhaps than the toxicity of the developing agents involved.

PE

 

[eclarke]

So...worrying about situations after you are long dead might be folly...

 

[Ian Grant]

I've been using Pyro toners for B&W prints for around 35 years, and more recently Pyro film dvelopers, the stains formed are remarkably stable. There's never been anything written (except speculation on this site) to suggest that the stain fades to cause any significant degradation.

There has been evidence produced that there is a very slight intial change in the dyes the first time negatives are printed from which while just measurable has no impact on printing and that then the negatives are stable.

We need to remember that all negatives tend to suffer slight deterioration over time, sometimes silvering out or affected by air-borne pollutants.

Ian

 

[Ian Grant]

It's worth remembering that all the major manufactuers made Pyro developers for many years and Kodak used Pyrocatechin in HC110 for a while so they were well tested by time.

Pyro dvelopers went out of favour because photographers began working in a different way with the advent of more modern emulsions and finer grain developers which was spurred on by the introduction of 35mm cameras. Before the mid-late 1920's plates and films were processed to very much higher contrasts and densities and papers were made to match those negatives but to get the best from smaller formats lower densities/contrast were require to get finer grain and better sharpness.

Ian

 

[Photo Engineer]

All dyes fade, period! Even if there are no tests to the contrary, this is a true established fact.

It may take 10 - 100 years, but they fade. The problem is that no one has run tests to determine how fast and under what conditions these dyes fade.

You spin the wheel and you take your chance.

PE

 

[pgomena]

I intend to enjoy using pyro developers as long as I'm alive. Not that many people care about my pictures now, so I don't anticipate any great clamor over the original negatives once I'm gone. I do my best to store them in polyethylene sleeves in a dry, dark space, so fading from light exposure is not an issue. I expect they will be just fine 50 years from now if anyone cares.

Peter Gomena

 

[Worker 11811]

So...worrying about situations after you are long dead might be folly...

Except for six rolls of film that I shot in 1995 that got sealed in the Bicentennial Time Capsule which is now buried under the cornerstone of City Hall and won't be opened until 2095.

(It was Tri-X Pan. Unless there is a major disaster like a flood or a tornado, I have no doubt the film will last 100 years.)

 

[nworth]

PE is correct about fading. But there are negatives developed in Pyro (in all sorts of formulations) that have been going strong for over a hundred years and are still quite printable. There are also a lot more that have deteriorated for unknown (possibly multiple) reasons. So, treated properly, it is possible to get long life out of some Pyro negatives. We don't know anything about the archival keeping properties of modern films processed in modern Pyro developers, however. Since they all contain a fairly vigorous silver image, they should be at least printable, possibly with some deterioration, in the distant future if they were properly fixed and washed. It might be interesting to run an accelerated aging test.

 

[Ian Grant]

PE is correct about fading. But there are negatives developed in Pyro (in all sorts of formulations) that have been going strong for over a hundred years and are still quite printable. There are also a lot more that have deteriorated for unknown (possibly multiple) reasons. So, treated properly, it is possible to get long life out of some Pyro negatives. We don't know anything about the archival keeping properties of modern films processed in modern Pyro developers, however. Since they all contain a fairly vigorous silver image, they should be at least printable, possibly with some deterioration, in the distant future if they were properly fixed and washed. It might be interesting to run an accelerated aging test.

The point that's constantly missed is the Pyro stains are very much more stable than any dyes used in colour films or prints, Kodachromes fade and disappear in 50 years but that hasn't happened to Pyro negatives as yet

There's a vast wealth of knowledge about various archives of photographers who used Pyro negs and no mention of issues of the stain fading.

Ian

 

[Photo Engineer]

A very large number of people have made side-by-side comparisons of Kodachrome and other chromogenic films and they have determined the amount of fade under various conditions. These are before and after comparisons with data. So, we know that they fade. There is no data regarding pyro or stained negatives. So, we can't prove either way whether they are more or less stable than any other dye.

The yellow-green stain is similar to the old Quink Green Ink sold in the US, and it was made from HQ which was oxidized into the Quinhydrone form to make the greenish yellow colored ink tint. This tint fades as I well know. All notes I took in green ink are virtually gone today. All dyes fade. This is a property inherent in the process which imparts their color. They absorb energy from light, heat and etc and gradually fade.

As I said earlier, no one can prove one way or another, but based on scientific fact, they fade. Just because there is no proof does not mean that they are stable.

PE

 

[Sal Santamaura]

Except for six rolls of film that I shot in 1995 that got sealed in the Bicentennial Time Capsule...It was Tri-X Pan...I have no doubt the film will last 100 years.)

Don't be so sure. As rolls, they were on acetate base. When that capsule is opened, they could be a vinegary blob. Shoulda shot polyester-base sheets.

 

[Kirk Keyes]

The stain in Pyro-developed films seems to me to be much more that a "dye". It's actually a chemically bonded cross-linking of gelatin molecules, which happens to have light absorbing properties.

I'm certain the cross-linking can be broken, but it appears the rate with normal storage conditions is not very great. Keep in mind that strong light storage is probably not going to be good for them.

I've no testing to support my suspicions, but based on anecdotal reports of the condition of properly stored vintage negatives, I suspect that "pyro-stained" gelatin should last about as long as the gelatin itself.

I guess we need the Wilhelm group to do a small test for us...

Kirk

 

[ic-racer]

I've been using Pyro toners for B&W prints for around 35 years, and more recently Pyro film dvelopers, the stains formed are remarkably stable.

It would be interesting to see that data.

 

[ic-racer]

It's worth remembering that all the major manufactuers made Pyro developers for many years and Kodak used Pyrocatechin in HC110 for a while so they were well tested by time.

Pyro dvelopers went out of favour because photographers began working in a different way with the advent of more modern emulsions and finer grain developers which was spurred on by the introduction of 35mm cameras. Before the mid-late 1920's plates and films were processed to very much higher contrasts and densities and papers were made to match those negatives but to get the best from smaller formats lower [silver] densities/contrast were require to get finer grain and better sharpness.

Ian

That would be an argument in favor of a staining developer.

 

[Worker 11811]

Don't be so sure. As rolls, they were on acetate base. When that capsule is opened, they could be a vinegary blob. Shoulda shot polyester-base sheets.

Point taken. On the plus side, we knew what we wanted to do from the beginning of the project. The film was processed by a local lab with specific instructions that they were going in the time capsule. They were supposed to be placed in polyester sleeves and sandwiched between layers of acid free paper (or something like that) in hopes that the paper would absorb and/or buffer any acetic acid vapor given off.

The capsule, about the size of a casket, is buried six feet under ground. It was supposed to have been vacuum sealed before it was buried.
Temperature should not be a problem because the temperature under ground never goes much above 50ºF.

If I remember correctly, a set of 4x6 B/W prints was also supposed to have been made and interred with the film.
It's been 17 years since it was buried. Memory fades...

My wife is an administrator at the local Historical Society. That's how I got the gig. (It was actually before we got married.)
I suppose I could ask her to look up the details.

 

[wlambert]

Thanks for the information and comments. With all the work that has been done on the archival aspects of silver negatives and prints it is surprising that very little has been done on the useful image life of negatives developed in pyro...or at least it is much harder to find. If you google something like "photographic conservation pyro negatives" you get some references, but I've found nothing yet specific to the subject.

As Photo Engineer noted dyes do fade, but Kirk considers the stain "to be much more than a 'dye.'" Obviously if it were a "stain" akin to rust (iron oxide) it wouldn't fade in (literally) a million years. As nworth noted even if the stain faded there is still silver there to make an image, but I wouldn't imagine it would be a very ideal one.

Fading aside, there is also the issue of possible deleterious reaction between the stain and the other components of the negative such as gelatin, silver grains, substrate, etc. Kirk's note that the stain is bound with the gelatin strikes me as either comforting or scary...depending.

Anecdotal evidence (Ian and nworth) indicates that pyro-stained negatives 50-100 years old are still very useful. That suggests that for most of our work we really shouldn't worry very much. Still, as Kirk says, it would be nice to have some experimental evidence...

Thanks,
Wayne

 

[Ian Grant]

Wayne, I'd go a few steps further because negative aren't stored in the light, so rather like cave paintings the risks of damage and deterioration caused by light are minimal. Then there's archives that are regulary worked with whose negatives would almost all have been made with Pyro based developers and we are talking about major collections here none of whom have reported issues of fading of Pyro stained negatives. In some cases the glass plate have been in use for making prints for well over 60-70 years.

Usually it's a case of finding (or proving) the cause of a known problem, however in this case it's speculation of a possible problems that's not been observed in practice in over 100 years.

There are other far less stable photographic processes like blue toning with Ferricyanide/Iron toners and kept in the dark they will last many years with no issues.

Ian

 

[pgomena]

I ran across cyanotype prints in the Oregon Historical Society's files that were at least 80 years old and still crisp and contrasty. They had been made by a college student on a budget, so I doubt the processing was to "archival standard" had there been one at the time. I also came across glass negatives there that probably were processed in a pyro developer, and the photographer took the extra step of varnishing the emulsion side of the negative. They were absolutely beautiful to scan or print 100 years from their creation.

Peter Gomena

 

[nworth]

Some years ago at the San Francisco Palace of the Legion of Honor I saw an early cyanotype (1860s, I think) that was as bright and clear as the day it was made. Most of its life was spent in various museum collections but not on display. Dark and good storage are beneficial.

 

[Vaughn]

Faded cyanotypes can be regenerated by putting them in the dark for awhile. Too bad the same does not hold for silver gelatin prints.

 

[Photo Engineer]

It can be done however, if one is willing to do the work!

PE