[pure-silver] Re: word from ilford
- From: Laurence Cuffe <cuffe@xxxxxxx>
- To: pure-silver@xxxxxxxxxxxxx
- Date: Wed, 15 Aug 2007 09:01:41 -0700
On Tuesday, August 14, 2007, at 11:39PM, "Richard Knoppow"
<dickburk@xxxxxxxxxxxxx> wrote:
>
>----- Original Message -----
>From: "Steve Nicholls" <gl1500@xxxxxxxxxxxxxxxx>
>To: <pure-silver@xxxxxxxxxxxxx>
>Sent: Tuesday, August 14, 2007 5:38 PM
>Subject: [pure-silver] Re: word from ilford
>
>
>> Eric Nelson wrote:
>>> I got a call from Mike Bain from Ilford/Harman, and
>>> his opinion, as well as one other person he consulted,
>>> is that these prints we've been discussing have
>>> suffered oxidative bronzing.
>>> Now to me bronzing has been a defect that presents as
>>> a reflective mirror effect with little or no
>>> discoloration such as an over exposed albumen print,
>>> but Mike assured me this is different and is
>>> attributed to pollutants of one kind or another.
>>>
>>>
>> I had three RC prints do virtually the same and it was the
>> glues used in the mounting. Not done by me. They were
>> mounted under glass.
>>
>>> [snip]
>>>
>>
>>> His only suggestion to prevent this from happening is
>>> selenium toning for a few minutes in either 1:19 or
>>> 1:31 dilutions.
>>>
>>> I had always thought that silver prints processed &
>>> washed well would be fairly archival and that selenium
>>> gives and added amount of stability for the truly
>>> paranoid and also cools the image, but it seems from
>>> this conversation that selenium is pretty much a
>>> necessary part of the silver process when sending off
>>> work to unknown environments and handling.
>>>
>>>
>> At the 1:31 dilution I doubt there would be any colour
>> change.
>> Afga Sistan is also recommend for similar reasons.
>> Apparently it has been re-released by AO ??
>>
>> Steve
>>
>
>
> There seems to be no research data on Sistan. It may
>very well work but I've never seen any proof.
Ctein "Post Exposure" (focal press 2000) has reported his tests of Sistan in
sufficient detail for any one who cared to reproduce them, to do so.
I also found a reference by Oren Gradon in the large format photography forum
to a recent thesis (May 2003) by Harald Sorgen, from the University of Applied
Sciences in Cologne, Germany
where Sistan was found to be effective. Against that we have the fact that
using in using sistan you are putting a permanently water soluble protective
coating in the print which may cause issues if the humidity of the print
environment is cycling, a point raised by Ryuji Suzuki in another forum. So it
it all boils down to: the only way to preserve an image permanently is is to
make sure it has salacious content and let it loose on the web.
All the best
Larry Cuffe
<large section snipped here>
> Note that in the past RC prints were subject to
>oxidation from a gas emitted by the Titanium Dioxide
>reflective layer beneth the emulsion. This effect was
>exagerated when the prints were mounted under glass or
>plastic, which prevented escape of the gas. This gas
>attacked both the image and the plastic layer causing it to
>craze and even flake off. Modern RC papers contain
>scavengers for these gasses and, in general, are about as
>permanent as fiber base paper. They will still benefit from
>proper protective toning or the use of stablizer.
>
>---
>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.
>
>
=============================================================================================================
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:
