Arcival Qualities of Pyrocat?

[Photoe]

What are the archival qualities of Pyrocat HD and/or MC? How does it compare to other film developers? Does the stain eventually fade?

 

[Ian Grant]

Early glass plates were usually processed in staining developers and there's no evidence they've faded any more or less than non stained negatives. Negatives get stored in the dark so fading is fad less likely take place anyway.

Ian

 

[pgomena]

Ditto Ian's comment. I worked with glass plate negatives from collections dating to the late 1800s and saw no archival advantages or disadvantages to pyro staining nor any differences between stained or unstained negatives as to their keeping qualities. Those developed in a staining developer maintained printing qualities as good as any other as well.

Peter Gomena

 

[Photo Engineer]

OTOH, the images do contain dyes and all dyes fade with time.

Having no comparisons, the above comments are what we call "single stimulus" which have no reference plate that was stored frozen as an example. If there was a perfectly stored reference, and the comparison was identical then it would be a perfect world, but as we know, this is not possible.

So, the exact answer to your question is "we don't know" and "the best we can do is say that the change appears to be acceptable so far".

PE

 

[Photoe]

Thanks

Thanks to you all. I have recently begun to enjoy pyrocat and was wondering about the dye fading issues. Sounds like it will be long after me before any "issue" arises.

 

[pgomena]

Yes, "single stimulus" or anecdotal evidence is all the evidence we have. Kind of like a lawyer going to trial with sketchy circumstantial evidence. In stating that the antique stained negatives lasted and worked as well as non-stained negatives, I have to admit that there is no way to know what kind of developer was used. Some bore an obvious stain, others little if any. Some were well stored and in remarkably good condition for their age. Others were in poor condition. As a good friend of mine said, it's a miracle any of them survived. I, too, am confident my pyro negatives will outlast me.

Peter Gomena