From: Linas Kudzma (lkudzma@earthlink.net)
Date: 02/22/02-10:34:33 PM Z
Eric,
I have not used any such ammonium based salts of platinum. Are you asking
about ammonium based Pt(II) salts, or an ammonium version of the Pt(IV)
salt? I belive that the higher oxidation state Pt(IV) in the so called
"NA2" from B&S is the reason for the contrast effect I was discussing. The
counterions, whether they be K+, Na+ or NH4+ may be mostly irrelevant to
the redox chemistry of the platinum. The way I see it, they should only
play an important role if they drasticly effect solubility of the salts.
I'm speculating here ....
Where do you get ammonium based Pt salts? I might want to give it a try.
Linas
> [Original Message]
> From: Eric Neilsen <e.neilsen@worldnet.att.net>
> To: <lkudzma@earthlink.net>
> Date: 1/16/2002 10:15:34 PM
> Subject: Re: Papers
>
> Linas, Have you tried using the ammonium based platinum salt or just the
> potassium based salt? I believe that you will see a rather large shift in
> contrast with it as well. I showed these results to Sullivan back in 1995
> in Santa Fe. I did not see, or remember a comparison to the ammonium
based
> salt in the paper you speak of. Did I miss something?
>
>
> Eric Neilsen
> Eric Neilsen Photography
> 4101 Commerce Street, Suite 9
> Dallas , TX 75226
> 214-827-8301
>
> Web Sites : www.ericneilsenphotography.com
> http://e.neilsen.home.att.net
> ----- Original Message -----
> From: "Linas Kudzma" <lkudzma@earthlink.net>
> To: "alt-photo-process-l" <alt-photo-process-l@sask.usask.ca>
> Sent: Wednesday, January 16, 2002 6:20 PM
> Subject: Re: Papers
>
>
> >
> > Witho,
> > I have not done extensive tests, but I have done some, and can say
with
> > absolute certainty that the so called NA2 platinum (Na2PtCl6) available
> > from B&S raises contrast considerably more that "normal" platinum. In a
> > test with 1:1 ratios of Pd/Pt, with each type of platinum, the so called
> > "NA2" complex gave a 3-4 step compresion of the scale when printing a
> > stouffer step tablet.
> >
> > The chemical explanation offered in the technical paper at the B&S site
> > makes perfect sense to me. It takes twice the amount of ferrous oxalate
to
> > reduce the Pt(IV) of the "NA2" complex to metalic platinum Pt(0). The
> > Pt(IV) complex uses up the available ferrous oxalate rapidly in areas of
> > lower exposure, and this compreses the scale.
> >
> > Linas
> >
> >
> > > [Original Message]
> > > From: Witho Worms en Jorien van Santen <verzet13@xs4all.nl>
> > > To: <lkudzma@earthlink.net>
> > > Date: 1/16/2002 2:52:22 AM
> > > Subject: Re: Papers
> > >
> > > I am curious if anyone has researched this contrasting agent except
for
> >
> > > Sullivan ? I was not able to detect significant changes in contrast
with
> >
> > > this product.
> >
> > > As far as I know and experienced the contrast is not more influenced
> than
> > by
> >
> > > adding just the 'normal' platinum solution to the palladium.
> >
> > >
> >
> > > Witho
> >
> > >
> >
> > >
> >
> > > ----- Original Message -----
> >
> > > From: "Linas Kudzma" <lkudzma@earthlink.net>
> >
> > > To: "alt-photo-process-l" <alt-photo-process-l@skyway.usask.ca>
> >
> > > Sent: Wednesday, January 16, 2002 4:13 AM
> >
> > > Subject: Re: Papers
> >
> > >
> >
> > >
> >
> > > > Wendy,
> >
> > > > What I was talking about was using what B&S calls NA2 platinum as
a
> >
> > > > contrast agent in place of B&S Sol#2. There is a good technical
paper
> >
> > > about
> >
> > > > this special platinum complex on the B&S web site.
> >
> > > >
> >
> > > > I'm surprised you can hang the sheets with B&S Sol#2 overnight. I
> found
> >
> > > > that anything with chlorate (as in sol#2) needed to be used promptly
> (a
> >
> > > few
> >
> > > > hours). It may be paper dependant? I don't use Platine.
> >
> > > >
> >
> > > > Linas
> >
> > > >
> >
> > > >
> >
> > > > > [Original Message]
> >
> > > > > From: Wendy Gollihue <wgolli@flash.net>
> >
> > > > > To: <lkudzma@earthlink.net>
> >
> > > > > Date: 1/15/2002 1:26:06 PM
> >
> > > > > Subject: Re: Papers
> >
> > > > >
> >
> > > > > Linas,
> >
> > > >
> >
> > > > >
> >
> > > >
> >
> > > > > I use the B&S palladium solution no. 3 that uses NaCl. I use the
> >
> > > Ferric
> >
> > > >
> >
> > > > > oxalates 1 $2 from B&S at 27%.
> >
> > > >
> >
> > > > >
> >
> > > >
> >
> > > > > Is your finding also true with palladium as the component. I
truly
> > have
> >
> > > > had
> >
> > > >
> >
> > > > > no problems hanging it (platine) all night in the dark but will
> listen
> >
> > > and
> >
> > > >
> >
> > > > > am willing to change to prevent upcoming difficulties that others
> have
> >
> > > >
> >
> > > > > experienced.
> >
> > > >
> >
> > > > >
> >
> > > >
> >
> > > > > Wendy (TX)
> >
> > > >
> >
> > > > >
> >
> > > >
> >
> > > > > ----- Original Message -----
> >
> > > >
> >
> > > > > From: "Linas Kudzma" <lkudzma@earthlink.net>
> >
> > > >
> >
> > > > > To: "alt-photo-process-l" <alt-photo-process-l@sask.usask.ca>
> >
> > > >
> >
> > > > > Sent: Monday, January 14, 2002 10:38 PM
> >
> > > >
> >
> > > > > Subject: Re: Papers
> >
> > > >
> >
> > > > >
> >
> > > >
> >
> > > > >
> >
> > > >
> >
> > > > > | Carl,
> >
> > > >
> >
> > > > > | Paper coated with only FeOx and metals, with the Pt component
> > being
> >
> > > >
> >
> > > > > | Na2PtCl6, can sit in the dark for days without any bad effect.
I'm
> >
> > > using
> >
> > > >
> >
> > > > > | Na2PtCl6 (sodium chloroplatiATE) as the contrast agent
(typically
> > 20%
> >
> > > of
> >
> > > >
> >
> > > > > | the metals). In fact, sometimes I like the prints better from
> such
> >
> > > > paper
> >
> > > >
> >
> > > > > | that sat in the dark overnight. Maybe this is due to a slower,
> more
> >
> > > even
> >
> > > >
> >
> > > > > | drying? This is for DOP prints on Cranes Cover 90 Natural.
> >
> > > >
> >
> > > > > |
> >
> > > >
> >
> > > > > | Previously, when I used chlorate for contrast, letting paper sit
> >
> > > > overnight
> >
> > > >
> >
> > > > > | was not possible. This was without a doubt due to side reactions
> of
> >
> > > the
> >
> > > >
> >
> > > > > | chlorate, which is a very reactive oxidizer. The Na2PtCl6 salt
is
> > very
> >
> > > >
> >
> > > > > | stable and a nice contrast agent.
> >
> > > >
> >
> > > > > |
> >
> > > >
> >
> > > > > | Linas
> >
> > > >
> >
> > > > > |
> >
> > > >
> >
> > > > > | > [Original Message]
> >
> > > >
> >
> > > > > | > From: Carl Weese <cweese@earthlink.net>
> >
> > > >
> >
> > > > > | > To: <alt-photo-process-l@sask.usask.ca>
> >
> > > >
> >
> > > > > | > Date: 1/14/2002 12:35:02 PM
> >
> > > >
> >
> > > > > | > Subject: Re: Papers
> >
> > > >
> >
> > > > > | >
> >
> > > >
> >
> > > > > | >
> >
> > > >
> >
> > > > > |
> >
> > > >
> >
> > > > > | > > Wendy: Internally sized. Very textured surface -- not good
> or
> >
> > > bad,
> >
> > > >
> >
> > > > > | just a
> >
> > > >
> >
> > > > > |
> >
> > > >
> >
> > > > > | > > question of whether you want that or not for a given image.
> >
> > > Tough,
> >
> > > >
> >
> > > > > | heavy
> >
> > > >
> >
> > > > > |
> >
> > > >
> >
> > > > > | > > paper. YOU HAVE TO "RE-ACIDIFY" IT for pt/pd printing,
> >
> > > >
> >
> > > > > |
> >
> > > >
> >
> > > > > | >
> >
> > > >
> >
> > > > > |
> >
> > > >
> >
> > > > > |
> >
> > > >
> >
> > > > > |
> >
> > > >
> >
> > > >
> >
> > > >
> >
> > > > Linas Kudzma
> >
> > > >
> >
> > > >
> >
> > > >
> >
> > > >
> >
> >
> >
> > Linas Kudzma
> >
> >
> >
> >
Linas Kudzma
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