Pt/Pd Restrainers - Alternatives to Potassium Oxalate

Discussion in 'Alternative Processes' started by Ian Leake, Aug 8, 2013.

  1. Ian Leake

    Ian Leake Subscriber

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    It seems that the UK has effectively banned potassium dichromate for private use (under it's implementation of the EU REACH directive). Does anyone know of any alternative restrainers other than potassium chlorate and NA2? I'd rather give up platinum printing than return to potassium chlorate, and NA2 only works with palladium.

    Thanks in advance.
     
  2. doughowk

    doughowk Subscriber

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    Never used it but Artenz also lists Sodium Dichromate as a restrainer.
     
  3. Ian Leake

    Ian Leake Subscriber

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    Thanks Doug - I hadn't thought of that one. I've not used it either. Has anyone any experience with it?
     
  4. TheFlyingCamera

    TheFlyingCamera Membership Council

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    You could start doing Ziatypes, which allow a wide range of contrast control agents from gold chloride to sodium tungstate, and they'll give you more of a platinum color to begin with.
     
  5. Ian Leake

    Ian Leake Subscriber

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    Thanks Scott. Isn't this a palladium-only process? I'm keen to keep printing platinotypes not palladiotypes (a personal preference). If I'm forced to switch process then I'll most likely switch to the Malde/Ware process because it works with platinum. That said, I'd rather not change process because this will change the tonal relationships for all my existing negatives :-(
     
  6. TheFlyingCamera

    TheFlyingCamera Membership Council

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    The base metal is palladium, but it will give you the look of Platinum. I haven't printed enough side-by-side comparisons to say for certain, but I don't think this would change all the tonal relationships. I defer to your experience and personal artistic judgement.
     
  7. Jim Noel

    Jim Noel Member

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    Hydrogen peroxide from the drug store. In the US that is a 3% solution. Dilute this 1+1 with water and i generally add 1 drop to the sensitizer for an 8x10 print. For small prints, dilute it more. The peroxide needs to be prepared immediately prior to each session because it loses the extra oxygen atom rather quickly. When you buy peroxide, check the expiration date to assure the freshness.

    I have used this for several years rather than dichromate.

    Jim
     
  8. M Stat

    M Stat Member

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    I do exactly the same procedure as Jim does. A 3% solution of H2O2 diluted 1:1 with distilled water for an 8x10 print.
     
  9. Ian Leake

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    Hydrogen peroxide sounds interesting? Can I vary the amount to change the contrast? And does it have any unpleasant side effects on the print?
     
  10. M Stat

    M Stat Member

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    Just like any oxidizer, if too much is used it can create a grainy effect. If you want to achieve more contrast, I suggest using the sodium platinum solution (available at Bostick & Sullivan, Santa Fe, NM) rather than the potassium platinum. In my work, I use palladium predominately, and use the platinum as the contrast agent, the 1 1/2% H2O2 is to keep the print free from chemical fog, which is what will happen if no restrainer is used at all. Some of my prints are pure palladium, and if you ever want to experience the true beauty of this medium, pure palladium is absolutely exquisite.
     
  11. Ian Leake

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    Thanks, I'll experiment a bit with this.

    And yes pure palladium prints can be exquisite, but more usually they are too brown and heavy for my taste. I've settled on an 85-90% platinum / 10-15% palladium coating with potassium oxalate and potassium dichromate. This gives a beautiful, delicate, warm-black with nice clean highlights and good shadows. I've spent a few years getting this process optimised, and I have no desire to lose it. I use pure palladium mostly for teaching or when I want to smother the shadow details.
     
  12. Vaughn

    Vaughn Member

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    The route I have taken is to make negatives that need no contrast agent (I am using a pd to pt ratio of about 3:1 ). Of course this does not help if one has older negatives with varying contrast.

    I do occasionally use some older roll film negs that need a contrast bump, so I use pd plus NA2 for those, and get a similar color and feel as my larger prints.
     
  13. Loris Medici

    Loris Medici Member

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    Ian, pop Pd (Ware-Malde or Ziatype) can give you dead neutral or even cold toned prints - you can get warm toned and split toned prints too. See this print for instance, it's a pure Pd Ziatype print. It's a simple process (doesn't need any kind of developer, just a citric acid first bath + a good rinse - some papers need EDTA+sulfite clearing bath though...) and works very nice. It's good to have control over the hue. Just try it, maybe you'll like it a lot.

    Regards,
    Loris.
     
  14. cliveh

    cliveh Subscriber

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    How about 5-methyl benzotriazole nitrate?
     
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