[pure-silver] Re: Any news from Ilford?
- From: "Richard Knoppow" <dickburk@xxxxxxxxxxxxx>
- To: <pure-silver@xxxxxxxxxxxxx>
- Date: Thu, 27 Jan 2005 23:08:09 -0800
----- Original Message -----
From: "Dave Valvo" <dvalvo@xxxxxxxxxxxxxxxx>
To: <pure-silver@xxxxxxxxxxxxx>
Sent: Thursday, January 27, 2005 11:18 PM
Subject: [pure-silver] Re: Any news from Ilford?
> Richard, the truth is that Ilford RC papers with a full
> slug of ID would
> degrade within 6 months of processing. What happens is
> the ID is not locked
> into the emulsion. It leaches through the resin layer
> into the paper fibers
> as it sits in the box before processing. After
> processing, the ID within
> the paper begins to oxidize and turns a pinky color with
> increased Dmin
> visible from both sides. Kodak RC papers never had this
> problem because
> their paper fibers contain antioxidants to neutralize any
> ID that migrates.
> Thus Ilford, with Deluxe paper, removed most of their ID
> from their paper
> but left a little in for shelf life pre-process stability.
> You should be
> able to detect it with the carbonate solution (high pH)
> Ryuji suggests.
> Some natural age tests I have run on Ilford Deluxe RC
> papers show the defect
> is still there but to a much, much lesser extent and it
> takes a longer time
> to be visible.
>
>
> Dave
>
I have old (about ten to fifteen years) Kodak and Agfa RC
prints which do not show this degradation. I don't see it on
old Ilford papers either but don't know for certain which,
if any, had DI in them. The one paper I do see the
pink-brown discoloration is Arista, which is Kentmere in
disguise. Again, I don't know if it was DI or not.
---
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx
=============================================================================================================
To unsubscribe from this list, go to www.freelists.org and logon to your
account (the same e-mail address and password you set-up when you subscribed,)
and unsubscribe from there.
Other related posts:
