Anyone here doing Gum Bichromate?

Discussion in 'Alternative Processes' started by david b, Jan 3, 2006.

  1. david b

    david b Member

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    I think the process is called gum bichromate.

    Anyone on apug doing it? This process I mean? :D
     
  2. BrianShaw

    BrianShaw Member

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    yes.
     
  3. donbga

    donbga Member

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    Yes.

    Don Bryant
     
  4. david b

    david b Member

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    Got examples?
     
  5. donbga

    donbga Member

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  6. donbga

    donbga Member

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  7. smieglitz

    smieglitz Subscriber

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  8. Shinnya

    Shinnya Advertiser Advertiser

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    Not yet, but about to... Just mixed gum solution, and it is sitting in my fridge...

    tsuyoshi
     
  9. cjarvis

    cjarvis Member

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    In your fridge?

    I have a couple tri-color gums in the gallery.
     
  10. Lukas Werth

    Lukas Werth Member

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  11. Shinnya

    Shinnya Advertiser Advertiser

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    Joe,

    I really like one of the images in the middle. I am trying to make exposures like that for one of my projects. How was it done? Were you just printing darker or you controlled the exposure while taking pictures? Sorry for changing the topic by the way...

    cjarvis,

    Yes, my gum solution is still in fridge. Well, I was told to do so, at least while I am mixing it. I am about to mix some dichromate solutions and put gum over Pd prints once I figure out a problem in Pd printing (which is described in another thread)...

    Warmly,
    Tsuyoshi
     
  12. smieglitz

    smieglitz Subscriber

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    Tsuyoshi,

    It is a bit of both. The negative was a Polaroid p/n film which was exposed for the Polaroid print so the negative was slightly underexposed. I deliberately printed it dark as well. Furthermore, it is a zone plate image which has diffused and lowered the contrast of the image.

    This BTW is the most difficult scan I've ever done because the dark areas are subtly separated. I had to make it a .gif file instead of a .jpg in order to get it close to the actual appearence of the print. If viewed on a Windows machine I suspect the result looks much more contrasty and darker than the actual print.

    Thanks.

    Joe
     
  13. Poptart

    Poptart Member

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    Hi. I've been doing gum for a couple of years.
    Yes, it should be kept refrigerated--unless you're using that tar-like substance that's sold pre-mixed as printer's gum, which is loaded with preservatives. Gum acacia is an organic substance and spoils more quickly in heat. I add a tiny dose of preservative to mine when I mix it.
    So tell us more about your ambitions and the materials you're using.
     
  14. donbga

    donbga Member

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    FWIW,

    I never put my gum in the fridge. If you are mixing it yourself you can add about 5ml of 100% thymol per liter of your gum mix (what ever your gum mix ratio is; 1 to 2, or 1 to 3, etc.).

    I just keep mine in a sealed container in my darkroom. It pours out with a slight tint but smells like a fresh band aid and works great! :smile:

    Don Bryant
     
  15. Kate Mocak

    Kate Mocak Member

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    I do gum as well (http://kate.photopoints.com)

    An excellent description of the process is in the Issue #1 of The World Journal of Post-Factory Photography. You can download the issue from www.alternativephotography.com (run the search through the site to locate the file. It's quite big and takes a while to download.)

    Kate
     
  16. Shinnya

    Shinnya Advertiser Advertiser

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  17. donbga

    donbga Member

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    Can you tell us a little about your technique?

    Don Bryant
     
  18. Shinnya

    Shinnya Advertiser Advertiser

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    Don,

    Sure, I would be happy to. Let me know what you would like to know.

    Warmly,
    Tsuyoshi



     
  19. donbga

    donbga Member

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    Just a general run down of your work flow. How you coat. What kind of pigments you use. Gum ratios, etc., etc.

    Don