Is pyro archival?

[Patrick Raymore]

Is pyro archival? Has there been any research to suggest it is as stable as a silver image?

[Gudmundur Ingolfsson]

I have contact printed and enlarged glass plates from the 1870ties both wet-plate collodion and gelatine (dry-plate) plates that were obviously developed with pyro developer ( at first you think the brown stain to be a sign of age or poor fix). Those were easy to print and I had not the feeling of deterioation, neither of the silver image nor the stain. The collodion emultion had begun to peal of the glass in some cases though.

[sanking]

Those of use who print with alternative processes using UV light have observed a slight loss in density with negatives that are printed many times. I presume that the density loss is stain density though I have never actually measured it. You notice is especially with negatives that are printed with a mask. If you remove the mask after ten printings or so the area that was masked will be slightly darker than the area exposed to light.

[Jim Ewins]

You may check with Formulary for more info than that which is in their catalog. www.photoformulary.com Jim

[Tim Curry]

I think it is more an issue with the fixing and washing than the developer. Proper fixing and washing is probably more important to the life of the negative than various developers.

That being said, Sandy mentions the problem of fading with respect to repeated exposures to U.V. light. This would be along the lines of proper storage for most people. Usually, a negative (or most prints for that matter) should not be exposed to massive amounts of ultraviolet light as it can eventually affect density. With proper care taken in development, fixing, washing and storage, it should be fine for many years.

I've seen a couple of Weston's negatives at the Center for Creative Photography and they have stood up well for over 80 years. Some have faded, but this is a fairly long time and who really knows how many times he printed a given film over the many years his career spanned? His negatives were developed in ABC pyro and have lasted a long time.