Ware's Palladium + contrast control
I've been trying out Mike Ware's Palladium method...using Ferric Ammonium Oxalate / Palladium chloride + Ammonium chloride. Ware talks about using humidy as a contrast control. I'm just wondering if any of the other contrast control methods used in tradtional pt/pd would work with Ware's Pd mix. I guessing that as it's a POP method (i'm getting close to full print out so far)that using dichromate in the potassium oxalate won't do much. Would Na2 or anything else in the sensitizer mix be worth trying? For the platinum salt, he uses Ammonium Tetrachloroplatinate(II), I have some Sodium Chloroplatinate Solution (20%). Would I have to mix that with some kind of ammonium salt before using that as the platinum component in the ware method?
Ware method allow to control the contrast with the humidity as does ziatype. but at low humidity level you'll need to develop it in any paltinuum developer as the Pop image will not be full.
Any contrasting agent will work to incaerse the contrat and sodium tungstate will also work to lower it. But Na2 work better with FOX than with Double ferric salt. dichromate in the sensitizer or potassium chlorate or H2O2 will do the job.
If you work over 60% RH the develpment won't do lot. and I find it better to work at higher RH .
For the platinum you will need to buy Ammonium Tetrachloroplatinate(II). adding ammonium to the sodium salt won't do anything. and your sodium salt is only a 20% solution and Ware use a 25% solution.
But you may use potassium cholorplatinite as use in traditionnal platinum , it will raise the contrast.
Thanks for the insight christian...I'm usually between 60-70% humidity in n.california so i'm getting quite full print out. I'll try some Pot. Chlorate or Pot. Dichromate in the sensitizer and see what happens.
I must confess i like seeing the palladiums as POP, if there was a sure fire way of controlling contrast it would be a great system. I wonder if building a big humidor would be difficult?
I'm not sure where to get Ammonium Tetrachloroplatinate (II)...i dont think artcraft who i usually use stocks it, I dont recall seeing it on the bostick site either...any ideas whom might have it?
Andrew & Nze,
Originally Posted by andrewfrith
Iím very new at this, so I hope I donít sound stupid. Isnít the contrast in ziatype primarily controlled chemically and not so much by humidity? I know humidity makes quite a difference in how far it prints out. Does it also affect contrast? Is Ware's method different from ziatype in how it reacts to humidity?
Isnít the contrast in ziatype primarily controlled chemically and not so much by humidity?
Sullivan and Weesse make a book to explain a easily usable process and ziatype is easy to use but to make it easy the decide to control the RH and most of they wrote in their book about ziatype is true if you work over 50% RH . Under you'll need a developer. I rememberý when Dick wrote the first text on ziatype and make it available on his web page that he talk using the process from low RH to higher one. He wrote that a dry ziatype can be done but must be develop and so on.
In fact everything is possible but he could be mind boggling if you see all the possibility first.
I know humidity makes quite a difference in how far it prints out. Does it also affect contrast?
In their book DS and CA decide to work with RH which give full POP image , if they hadn't done that there will be a whole book on ziatype and all the possible variation from pizzigheli to sodium metaborate developer and so on.
Is Ware's method different from ziatype in how it reacts to humidity?
That's the point DS and CW decide to control the contrast chemically ( with bichromate, gold, sodium tungstate or special ferric salt) , Ware decide to control the contrast by the humidity these are 2 differents path but both works
The only thing I don't find clear with the Ware version is that in fact it is not a totally POP,process if you want to control the contrast by his method you still need to develop you print if you don't have the right DR in your negative.
Andrew I think BS should have some in stock but do not list it and artcraft should also have some. but if you want large quantity you may contact some chinese company.
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If you're under 50% RH, you should humidify the paper prior to coating and the Ziatype is still a POP process. I had some success during the winter doing this. Contrast control is usually done with dichromate, or maybe even the tungsten solution. Using the different metals will give a different look to the prints and may also increase contrast, depending on which metal and how much you use.
The Na2 doesn't get along well with the ammonium ferric oxalate (not sure why), but I was told by B&S that it might work with the sodium ferric oxalate. I am hoping to look into this soon.
I live in an area with as variable a RH as seems possible...as low as 20% in winter and as high as 80% in summer, which is why I abandoned zias - lovely as they are - and just started using DOP. Pure Pd DOP is reasonable and contrast is easily controlled a number of ways. Not prescribing a different process, just letting you know what my solution was to the humidity issue.