From: Sandy King (sanking@CLEMSON.EDU)
Date: 01/14/02-12:18:24 PM Z
Ken,
My understanding of both the mechanism of yellowing of albumen
prints, and of its long-term consequences, is that it is both
different and more serious than recent messages by you and Michael
Steinle would suggest. What I know is based largely on James Reilly's
book, The Albumen and Salted Paper Book, so if you know other
authoritative sources which may cast new light on the issues involved
I would like to know them. I quote two particularly significant
passages form Reilly (available at
http://albumen.stanford.edu/library/monographs/reilly/chap11.html).
First, on the cause of yellowing.
"The probable origin of the yellowing phenomenon in albumen paper is
the chemical bonding of silver to sulfur-containing side groups on
the protein molecules of albumen, some of which have a very high
affinity for silver. The silver bonded during sensitization to these
sites on the protein is so tightly held that treatment in hypo is not
sufficient to remove it. Thus a small amount of silver remains in all
areas of a fixed albumen print; the conversion of this silver to
silver sulfide is the immediate cause of the yellowing phenomenon."
Since historical prints made by other processes do not generally
exhibit this type of yellowing it is probably safe to assume that it
is limited to albumen prints, and/or other prints with a substrate
that consists in part of whole of albumen.
Second, on the severity of the problem, Reilly write:
"On the other hand the imperceptibly slow fading process and staining
of the highlights in historical albumen prints may be proceeding at a
rate which will lead to very severe image deterioration long
deteriorate. What this means is that possibly in another 75 years,
not a single albumen print will at all resemble its original
appearance."
I am truly very happy to know that some of Watkins' prints of
Yosemite from the 1860s have survived so well. However, I don't
believe one can be certain that these prints have not already
yellowed significantly, or that they will not do so in time unless
some remedy can be found to reverse or stop a reaction which appears
to happen with almost 100% of albumen prints.
Sandy King
>Sandy,
>
>I have seen orginal Watkins prints of Yosemite that are neither yellow or
>cracked. Since these are the oldest prints , with the exception of salt, in
>the world I think this is our best example. The salt prints that I have
>seen, only pictures of them, ...now they seem faded or worse. Most likely
>due to poor fixing I would suspect. This of course leaves out tintypes,
>ambrotypes and Dags which are all doing well. Once again most likely due to
>their substrates.
>
>..-----Original Message-----
>..From: Sandy King [mailto:sanking@clemson.edu]
>..Sent: Saturday, January 12, 2002 11:36 AM
>..To: alt-photo-process-l@skyway.usask.ca
>..Subject: RE: Albumen - How Archival
>..
>..
>..Yes, we still have them but they have all either already yellowed, or
>..will yellow with more time. As far as I have been able to determine
>..there is nothing to stop or reverse the yellowing process.
>..
>..Sandy King
>..
>..
>..
>..>We still have them from the mid 1800's. Gold toning is
>..recommended. I think
>..>the paper type is the biggest concern once toned.
>..>
>..>..-----Original Message-----
>..>..From: George Huczek [mailto:ghuczek@sk.sympatico.ca]
>..>..Sent: Saturday, January 12, 2002 10:44 AM
>..>..To: alt-photo-process-l@skyway.usask.ca
>..>..Subject: Albumen - How Archival
>..>..
>..>..
>..>..If done properly, how archival can one expect albumen prints
>..to be? Does
>..>..anyone have any suggestions for how increased permanence can
>..be obtained
>..>..with this process?
>..>..
>..>..
>..
>..
>..--
>..
--
This archive was generated by hypermail 2b30 : 02/15/02-11:47:41 AM Z CST