[alt-photo] Re: potassium phosphate

[Eric Neilsen]

You will get cooler prints, simply by changing the ion to NH4 instead of Na2 than using the cold tone developer. That may be a bigger deal for you if all your pd is bought mixed, but quite easy if you buy powder and mix to liquid.  

Eric Neilsen
4101 Commerce Street, Suite 9
Dallas, TX 75226
214-827-8301

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-----Original Message-----
From: alt-photo-process-list-bounces at lists.altphotolist.org [mailto:alt-photo-process-list-bounces at lists.altphotolist.org] On Behalf Of Loris Medici
Sent: Monday, June 28, 2010 3:05 PM
To: The alternative photographic processes mailing list
Subject: [alt-photo] Re: potassium phosphate

Doesn't post-humidification (and/or exposing relatively humid paper) help in getting cooler print tones with develop-out pt/pd?

IME, FWIW, AFO + Na2PdCl4 gives pretty cool print color (with considerable print-out) with - relatively - humid paper. Also, a "small" amnt. of gold-chloride in sensitizer also helps cooling print color - could be tried along with AFO + Na2PdCl4, IMHO... (Too much will give graininess and what not!)

Regards,
Loris.


On 28.Haz.2010, at 21:37, Clay Harmon Website wrote:

> I use this so-called 'cold bath' formula when I am doing workshops. I don't like the idea of having a bunch of people slopping around hot potassium oxalate in a closed space. 
> 
> I find that the image tone from this developer is actually pretty similar to straight 110degree potassium oxalate when the cold bath is used at room temperature. If it is cold tone you are looking for, I would stick with the pt/pd + gold toner that you are using. 
> 
> According to the Bostick-Sullivan site, the cold bath developer can produce cold toned prints when used at 50 degrees F, but apparently loses a lot of speed. I have never tried using it at that temperature, so I can't convey any direct experience. However, I can say that the cold bath formula used at around 70 degrees F is not radically different in print tone than the regular potox developer used slightly warm. 
> 
> Clay
> On Jun 28, 2010, at 12:47 PM, David Ashcraft wrote:
> 
>> I had read that it was possible to produce a blue tone using this.  The pics are winter scenes of ice and snow and printing them in warm tones isn't the look I want.  My other pics are in pt/pd so I want to keep using these materials.  I used the ammonium citrate and gold but wanted to go still cooler using the developer to do so.
>> 
>> What formula are you using?
>> 
>> David
>> On Jun 28, 2010, at 4:16 AM, Jon Reid wrote:
>> 
>>> I use it all the time David. I use it typically around room temp (~20-23)℃. It's a reasonably subtle difference depending on paper but on Arches platine it produces quite a nice tone just warm of neutral. I'm wanting to explore Ammonium Citrate for it's alleged cooler tones and slightly higher contrast but am having trouble sourcing any locally.
>>> 
>>> I'm also going to explore adding Gold chloride to my mix to explore it's tone changing characteristics though I've read arguments for and against.
>>> 
>>> Jon
>>> 
>>> 
>>> On 28/06/2010, at 2:55 AM, David Ashcraft wrote:
>>> 
>>>> Has anyone used potassium phosphate with potassium oxalate as a pt developer?  I want to make pt prints in a cooler tone, any suggestions?
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