[pure-silver] Re: Selenium toning + Agfa Sistan

I believe that the ideo behind Sistan came from the observation that gold toners
containing thiocyanate offered protection even when the gold salt was eliminated
from the toner.

Jerry

-----Original Message-----
From: pure-silver-bounce@xxxxxxxxxxxxx [mailto:pure-silver-bounce@xxxxxxxxxxxxx]
On Behalf Of DarkroomMagic
Sent: Thursday, November 25, 2004 7:11 PM
To: PureSilverNew
Subject: [pure-silver] Re: Selenium toning + Agfa Sistan


We may never get the complete story (Agfa doesn't have a research staff anymore
either), but they are talking about Sistan working on silver salts produced
through oxidation in the print's future. Remember, Sistan is applied to the
print and should not be washed out afterwards. It is staying in the print to
work on future silver oxidations, turning them into insoluble silver compounds.
The text says that these compounds build the protective layer at that time.

Selenium and KBT will protect the silver from this oxidation by forming mor= e
stable silver selenide and silver sulfide, respectively. Hence, Sistan has
nothing to do work on in a fully toned print. However, these toner conversions
are never 100%, and that's why I like the Sistan treatment in addition to
toning.

IMHO, Sistan is not a replacement for toning as this brochure promotes. The= n
again, using Sistan without prior toning is better than using no print
protection at all. However, there are arguments that Sistan might not be needed
if the print has been toned. I just like to be sure, and Sistan cannot hurt as a
final treatment, if its residue is wiped off.




Regards



Ralph W. Lambrecht




On 11/25/04 11:56 PM, "Claudio Bonavolta" <claudio@xxxxxxxxxxxx> wrote:

> Thanks Ralph,
>=20
> This is how I thought Sistan works but I've had a doubt while reading 
>the=
ir
> documentation (sorry, I
> found it in german only): 
> http://www.agfaphoto.com/de/photo/pdf/products/Sistan_Broschuere_2003_
> D.p=
df
> and particularly on page 4:
> --------------------------------------------------------------------
> "Ausfallende" Wirkung mit Schutzmantel.
> Durch die Behandlung mit Agfa SISTAN wird das sich durch Oxidation 
> bildende Silbersalz als farblose, unl=F6sliche Silberverbindung 
> ausgef=E4llt. Diese neu entstandene, vorteilhafte Sibersalzverbindung 
> ist lichtunempfindlich, sehr stabil und umh=FCllt das Silberkorn wie
> ein Schutzmantel.
> F=FCr hohe Archivfestigkeit und eine Stabilit=E4t, die fast
> den Konservierungsgrad einer Schwefeltonung erreicht.
> --------------------------------------------------------------------
> It seems like, but maybe it's just my german which is very limited, Sista=
n
> creates a layer of silver
> salts protecting the metallic silver.
> And thus my question, will it create this layer if the metallic silver 
>is  already covered with  selenium ?
>=20
> I hope you're right, Sistan looks like a very convenient solution to prot=
ect
> prints without
> modifying their aspect (or prints toned with toners not very 
>archival). =20  Best regards,
> Claudio Bonavolta
> http://www.bonavolta.ch
> ----- Original Message -----
> From: "DarkroomMagic" <info@xxxxxxxxxxxxxxxx>
> To: "PureSilverNew" <pure-silver@xxxxxxxxxxxxx>
> Sent: Thursday, November 25, 2004 1:11 AM
> Subject: [pure-silver] Re: Selenium toning + Agfa Sistan
>=20
>=20
>> Claudio
>>=20
>> Think of selenium and sulfide as creating 'protective layers' of 
>>modifie=
d
>> silver. Think of Sistan as a 'pollution sponge' added to the paper to 
>> be there 'just in case'. The function of Sistan is very different 
>> from that=
 of
>> toners but not unlike the function of calcium carbonate to 'buffer' 
>> moun=
t
>> boards to protect them from potential pollution attacks in the 
>> future. U=
se
>> it in addition to toning prints, not as a replacement.
>>=20
>>=20
>>=20
>>=20
>>=20
>> Regards
>>=20
>>=20
>>=20
>> Ralph W. Lambrecht
>>=20
>>=20
>>=20
>>=20
>> On 11/25/04 12:30 AM, "Claudio Bonavolta" <claudio@xxxxxxxxxxxx> 
>>wrote: =20
>>> Dear All,
>>>=20
>>> I like light (1+19) selenium toning because of the increased Dmax it 
>>>gi=
ves
>>> to
>>> the prints without a
>>> important change of color (well, with Ilford MG FB).
>>> As it seems selenium toning with this concentration is no more the 
>>> pana=
cea
>>> to
>>> keep our prints alive,
>>> will an additional bath of Agfa Sistan help in any way ? Or, in 
>>> other words, can Sistan still make the protective layer once the=
re is
>>> a
>>> layer of selenium ?
>>>=20
>>> Thanks,
>>> Claudio Bonavolta
>>> http://www.bonavolta.ch
>>>=20
>>>=20  
>>>=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>>>=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D
>>> =3D=3D 
>>> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
>>> D=3D=3D=3D=3D=3D=3D=3D=3D
>>> To unsubscribe from this list, go to www.freelists.org and logon to you=
r
>>> account (the same e-mail address and password you set-up when you
>>> subscribed,)
>>> and unsubscribe from there.
>>=20
>>=20
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
>
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> =3D=3D=3D=3D=3D=3D=3D=3D=3D
>> 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 
> fro=
m
> there.
>=20
>=20  
>=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
>D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
> 3D=3D=3D=3D=3D=3D=3D=3D
> 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 subscri=
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