Re: Another Ziatype question

HI Loris

for clearing I use 2 bath of sodium sulfite and one of Kodak Hypo wash . I
print with clear border to check my clearing and I got no stain.

You should also try and a well known paper as Kid finish Cranes or Arches
platine.

Jeffrey, I find no use by using more concentrated solution of Palladium, it
don't yeld better Dmax. I give a try to your formula for zia and with my
paper Cot 320 and Buxton there is no difference . It surely work with some
paper but with good paper even a more dilute solution work.

Amicalement
best regards

Nzé Christian
mailto:christian_nze@hotmail.com
http://www.c-nze.com

>From: Ryuji Suzuki <rs@silvergrain.org>
>Reply-To: alt-photo-process-l@sask.usask.ca
>To: alt-photo-process-l@sask.usask.ca, sanking@CLEMSON.EDU
>Subject: Re: Another Ziatype question
>Date: Mon, 11 Oct 2004 14:03:49 -0400 (EDT)
>
>From: Sandy King <sanking@CLEMSON.EDU>
>Subject: Re: Another Ziatype question
>Date: Mon, 11 Oct 2004 13:50:26 -0400
>
> > Have you checked the pH of your developer? Staining that can not be
> > cleared results from the formation of iron hydroxide from residual
> > ferrous iron, Fe(2+) in an alkaline environment. In kallitype
> > printing staining can take place during both development, if the
> > developer is alkaline, or during washing, if the tap water is too
> > alkaline. The iron content of the tap water, in combination with a
> > high pH, may also play a role. I suspect that the same goes for
> > Pt./Pd. printing since residual ferrous iron is a reduction
> > by--product.
>
>I don't practice those processes myself, but I can add a bit about
>iron chemistry.
>
>Unless the solution contains reducing agents, Fe(II) ions are
>converted to Fe(III) in neutral to alkaline pH, and make ferric
>hydroxide like you mentioned. If the intention is removal of iron, it
>is best you don't let this happen. I would try acid DTPA or EDTA
>solution to facilitate removal of iron.
>
>--
>Ryuji Suzuki
>"You have to realize that junk is not the problem in and of itself.
>Junk is the symptom, not the problem."
>(Bob Dylan 1971; source: No Direction Home by Robert Shelton)

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Received on Mon Oct 11 12:54:42 2004