Is it possible just to replace collodion with gelatine for tintype?

Discussion in 'Alternative Processes' started by OmerYair, Aug 16, 2012.

  1. OmerYair

    OmerYair Member

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    I'm about to dive into wet-plate (tintype) and wondered if it is possible to replace the collodion with gelatin and get sort of dry plate?
    [Maybe a little chrome alum to harden the gelatin will be needed]

    Am I missing anything? From early photography literature, gelatin emulsions seems to be faster than collodion and the only "drawback" is that gelatin is not as glossy.
     
  2. Mike Wilde

    Mike Wilde Member

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    From casual exposure to the process, I thought the coliodion was 'sticky', in a way that gelatin is not at room temperature.
     
  3. OmerYair

    OmerYair Member

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    I don't think the stickiness is what makes the process work (collodion does have to remain somewhat wet to make the process work).

    The chemical reaction is as follows: The salts in the collodion form into silver halide sesitive to light when they come into contact with silver nitrate. After plate exposure it is normal dev/fix processes.

    By replacing collodion with gelatin one can sensitize a gelatin+salts plate in the same way and use it whenever he likes without the rush before everything dries up. I think that some addition of chrome alum might be needed to make sure none of the gelatin melts during the process when submerged in any solution.
     
  4. Jerevan

    Jerevan Subscriber

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  5. kevin klein

    kevin klein Member

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  6. Jerevan

    Jerevan Subscriber

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    I usually recommend your article Kevin, but I can't repeat myself all over all the time I thought, so I took another one of the recipes from The Farm this time. :smile:

    And I guess you could just speed up Chris' recipe by washing the emulsion instead of letting it sit overnight, etc. I guess anything is possible, just pick one that suits your style of working and go for it.
     
  7. OmerYair

    OmerYair Member

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    Kevin, your method seems very simple indeed. Why don't you add any gelatin hardener in the mix (glyoxal/chrome alum/...)?

    Also, you write that a thicker emulsion yields better results - do you use some sort of frame when you coat or just let the gelatin flow and cover the plate like collodion?
     
  8. kevin klein

    kevin klein Member

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    I leave out the hardener so the plates can be cleaned off with warm water, if the plate is a good one I can harden it before drying.

    To me, the thicker emulsion provides a better density because there is more thickness to the image. The other emulsion I used was very thin and did not give negatives to be printed out. I just pour the plate like collodion, drain, and set on a leveling table.

    The last time I made an emulsion I did not use any hypo sensitiser and it worked fine, so I think that step can be eliminated.
     
  9. Jerevan

    Jerevan Subscriber

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    Leaving out the hypo just makes the emulsion slower as far as I understand it, nothing else happens.