RE: NA2 For Pt/Pd BLENDS

Eric,

I am not advocating any specific kind of approach. The use of
platinic acid sounds like a good way to control contrast for those
who really want to work with traditional PT/PD blends.

I could personally care less whether one calls a print made with
palladium and a tiny bit of Na2 a palladium print or PT/PD. However,
I don't see that a print made from a 1:3 blend of PT/PD has any more
right to the name PT/PD than a print made from pure palladium to
which a little Na2 has been added. Ultimately they are both made from
blends, the only difference being the ratio. And the fact of the
matter is that a very little bit of Na2 has a much bigger impact on
the contrast of a palladium print than you could get with a PT/PD
blend of 1:3, or even 1:1 for that matter.

Sandy

>Sandy, Each different developer has the ability to introduce a different
>contrast range as well color. Ammonium Citrate has a different contrast
>than Pot Ox, and Sodium Acetate. Why on earth do I want to change the
>contrast with two things at once to control color when I can do it with just
>one? I might as well add a little AFO and really move things around. I find
>that adding an amount of H2 (Platinic Acid) instead of Na2 ( new magic
>bullet) allows for contrast control and doesn't mess with the color of the
>prints with blends.
>
>I realize that we all come to our printing methods from many different paths
>and far be it from me to preach the virtue of one above another. If printers
>are wanting to call their prints PT/PD prints due to the addition of several
>drops of a highly diluted PT solution then so be it but my name is not in
>that camp.
>
>
>
>Eric Neilsen Photography
>4101 Commerce Street
>Suite 9
>Dallas, TX 75226
>http://e.neilsen.home.att.net
>http://ericneilsenphotography.com
>
>
>> -----Original Message-----
>> From: Sandy King [mailto:sanking@clemson.edu]
>> Sent: Sunday, December 07, 2003 9:13 AM
>> To: alt-photo-process-l@sask.usask.ca
>> Subject: RE: NA2 For Pt/Pd BLENDS
>>
>> Eric,
>>
>>
>> No, I am not saying that Na2 does not effectively control contrast
>> with a blend of PT/PD, only that my initial observation that it did
>> could not be supported from the data in my tests.
>>
>> But what I am suggesting is that there is really no any reason to put
>> any platinum in the blend other than Na2. You can get excellent
>> contrast control with just palladium and Na2, the addition of Na2
>> allows you to call it a PT/PD print, and if you are after a
>> particular color you can get it by choice of developer rather than by
>> blending platinum and palladium.
>>
>> Sandy
>>
>>
>>
>>
>>
>> >Sandy, Am I right to understand then, that what you are saying is that
>> Na2
>> >does not effectively control contrast with a blend of PT and PD? I have
>> not
>> >see Dick Arentz' writing, nor that of B&S, other than the paper posted on
>> >the B&S site.
>> >
>> >Eric Neilsen Photography
>> >4101 Commerce Street
>> >Suite 9
>> >Dallas, TX 75226
>> >http://e.neilsen.home.att.net
>> >http://ericneilsenphotography.com
>> >
>> >
>> >> -----Original Message-----
>> >> From: Sandy King [mailto:sanking@clemson.edu]
>> >> Sent: Saturday, December 06, 2003 1:59 PM
>> >> To: alt-photo-process-l@sask.usask.ca
>> >> Subject: Re: NA2 For Pt/Pd BLENDS
>> >>
>> >> Bob,
>> >>
>> >> I meant to say the opposite, that is, you get about the same
>> >> contrast, speed and color with 100% palladium as with a 1:3 blend of
>> >> platinum and palladium. The color is very warm brown in both when
>> >> developed in a 25% solution of potassium oxalate at 120F. If you go
>> >> all the way to a 1:1 blend of platinum and palladium the color is
>> >> just a tad less warm. This is without the addition of any Na2.
>> >>
>> >> With sodium citrate at room temperature, which I have also used with
>> >> palladium, the color of both pure palladium and pt/pd blends is much
>> >> less warm, and with ammonium citrate at room temperature the color of
>> >> pure palladium is almost neutral, just slightly warm.
> > >>
>> >> Conditions of RH and temperature may give different results, but the
>> >> above is what I see in my working conditions of about 70F and 55-65%
>> >> RH.
>> >>
>> >> Considering all of this it makes sense to use pure palladium, control
>> >> contrast with Na2, and get the color you want with choice of
>> >> developer.
>> >>
>> >> Sandy King
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >> >DEAR SANDY (et al.)
>> >> > Thanks so much for sharing all of your experience on this
>> topic.
>> >> > Sandy, I use Sodium Citrate developer at 100 F and have
>> repeatedly
>> >> >found definite differences in image color between 100% Pd and 1:3
>> >> >Pt/Pd, all other variables being constant.
>> >> > What I understand from your last posting is that I will get
>> >> >contrast changes with my blend similar to what one gets using Na2
>> with
>> >> >pure Pd. Thanks. This will be a great starting point for testing
>> >> >saving me a lot of wandering in the forest.
>> >> > Thanks again!
>> >> > CHEERS!
>> >> > BOB
>> >> >
>> >> >----- Original Message -----
>> >> >From: Sandy King <sanking@clemson.edu>
>> >> >Date: Friday, December 5, 2003 6:03 pm
>> >> >Subject: Re: NA2 For Pt/Pd BLENDS
>> >> >
>> >> >> Clay,
>> >> >>
>> >> >> In looking back through my notes I now realize that I put my mouth
>> >> >> ahead of sound analysis. It is now apparent to me from my own data
>> >> >> that my method of testing Na2 in Pt/Pd blends used such small
>> >> >> quantities that the amount of pure palladium continued to be the
>> >> >> dominating factor, so in essence I got the same ES with pure
>> >> >> palladium and blends that contained as much as 50% platinum.
>> >> >>
>> >> >> Fortunately my observations had nothing to do with the essential
>> >> >> testing I did, which was to compare the impact of different UV
>> >> >> sources on various blends of palladium and platinum, except for
>> >> >> the
>> >> >> fact that the amount of Na2 used was too small to merit analysis.
>> >> >>
>> >> >> However, without Na2, or any other contrast controlling agent in
>> >> >> the
>> >> >> mix, I got virtually the same exposure scale speed, and color from
>> >> >> the use of: 1) 100% pure palladium; 2) a 1:3 blend of Pt/Pd; and
>> >> >> 3)
>> >> >> a 1:1 blend of Pt/Pd. This was with a developer of 25% potassium
>> > > >> oxalate, used at 120 F.
>> >> >>
>> >> >> Which is to say again, I really can't see any reason for putting
>> >> >> any
>> >> >> platinum in the blend except for the Na2 which is needed for
>> >> >> contrast
>> >> >> control.
>> >> >>
>> >> >>
>> >> >> Sandy
>> >> >>
>> >> >>
>> >> >>
>> >> >>
>> >> >> >On Dec 5, 2003, at 2:16 PM, Sandy King wrote:
>> >> >> >
>> >> >> >>Clay,
>> >> >> >>
>> >> >> >>That is interesting, but it definitely worked here.
>> >> >> >>
>> >> >> >>Have you tested this?
>> >> >> >
>> >> >> >Not personally. I'm just parroting what I read last night. Next
>> >> >> time
>> >> >> >I do some printing, I'll run an endpoints test and do a test with
>> >> >> >pt/pd/FO at 3/3/6 and one with Na2/Pt/Pd/FO at 2/2/2/6 and see
>> >> >> what
>> >> >> >I get.
>> >> >> >
>> >> >> >Clay
Received on Sun Dec 7 11:58:24 2003