Calotype problems

Discussion in 'Alternative Processes' started by GCyberfish, Sep 12, 2007.

  1. GCyberfish

    GCyberfish Member

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    A few Weeks ago I tryed the Talbot´s Calotype Process - and completely failed.
    I used paper for painting.
    Washing the paper in silver nitrate solution, then iodizing - everything was okay. But when I washed the paper with Talbot´s "Silver-gallo-nitrate"
    (I ve already used the recipe for toning prints), and the paper went totally black - all the silver chloride in the paper had been reduced.

    recipes:
    Bath one
    silver nitrate 6,5g
    Water to make 200ml

    bath two - iodizing
    potassium iodide 32,5g
    Water to make 600ml


    Silvergallonitrate

    Bath a
    silver nitrate 6,5g
    Water 60ml
    Acetic acid 60% 10ml

    bath b

    saturated solution [ acidum tannicum] - german "Tannin" - don´t know the english word for it-


    I hope you can help me.
     
  2. Jim Noel

    Jim Noel Member

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    I don't know if I can help or not, but-
    I see no listing of gallic acid in your process and this is a necessary ingredient in the calotype process. Is this the "tannin" in part b?

    What kind of light levels were you working under? I use a red safelight, 15 watt at 4+ feet.

    Was each step dried in total darkness?

    Was the silver-gallo-nitrate the same actual solution in which you had toned prints, or fresh solution. If previously used, this may be the culprit.

    I hope these questions help you to track down your problem.
     
  3. GCyberfish

    GCyberfish Member

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    the "Tannin", I found out, is simply tannic acid, and I used it as a substitution
    for the gallic acid.
    and I used red safelight...
    ...but is the drying in total darkness really nessesary for the Process?
    I used a device for dry pressing paper as a heat source, so the paper is dry after a few minutes.

    Could´nt it be the paper? Residual chemicals from the paper-bleaching process could be the causation for the undesired reaction.
    To get further I have to get to know more about the production process of paper...
     
  4. markm

    markm Member

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    I will admit up front that I have no hands on experience yet.

    According to "Coming into Focus", the sensitized paper should be moist when exposed.

    Prepare the paper with a 7.5% solution of silver nitrate and 5.6% solution of potassium iodide.

    For sensitizing and developing, the book refers to 4 solutions:

    A) 11.4% solution of silver nitrate
    B) 28.4ml A, add 5.5ml glacial acetic acid
    C) Using 100 ml water, make a saturaed solution of gallic acid
    D) Add 3 drops B and 3 drops C to 4ml water

    To sensitize the paper (under safelight), coat the prepared paper with D and let sit for 2 minutes. Blot the paper and let dry in the dark. "The paper will be slightly moist when put into the camera."

    To develop (under safelight), mix equal parts B and C and brush onto the negative. An image should appear at once. With a clean brush apply C - do not over-wet. Allow the image to develop until it stops increasing in density - apply more C.

    When you have a good contrasty image, rinse in plain tap water, fix with hypo for 5 minutes, then rinse for an hour.

    - Mark
     
  5. cynan

    cynan Member

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  6. Jerevan

    Jerevan Subscriber

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