clearing the kallitype

Discussion in 'Alternative Processes' started by philsweeney, Aug 15, 2004.

  1. philsweeney

    philsweeney Member

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    I have been using 3% citric acid for clearing per Sandy's article. Using platinotype (gold toned) I find the image bleaches too much at 4 min and is much more acceptable at 2 min. I have seen references that suggest 2 minutes may be adequate. I am using a step tablet so I can see significant areas of same tone. I have had no stain in the unexposed sensitized area after 8 min development in sodium citrate - not ever, not once. So the print appears to be clear before it hits the clearing bath. Oddly enough in Dick Steven's book there is reference to a clearing bath that includes sodium citrate and citric acid, which was recommended for use after developing in sodium acetate.

    Is it possible the print is completely cleared in the developer (using sodium citrate)?

    I thought I’d try a 1% or 2% solution of citric acid for different times. But if the image has no stain to clear how can I analyze whether all iron compounds have been removed? I checked the test on Jeffery Mathias’s website and I could not understand the procedure. Perhaps someone can clarify the procedure for me:
    http://home.att.net/~jeffrey.d.mathias/guidep/clearing_test.htm

    Do I process normally after applying the 1% solution of Potassium Ferricyanide ?
     
  2. sanking

    sanking Member

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    Phil,

    There are actually two tests on Jeffrey Mathias' site. With one you simply coat the paper, taping part of it to creat a line between coated and uncoated area. Remove the tape, draw a line between the two areas, and process normally to test your procedures. The second test involves the indicator and I don't follow completely how tht works.

    I suggest you try the test above, cutting the test sheet into three or four pieces. Then develop each, without any exposure, for yournormal development time sodium citrate and, then clear for different times in citric acid, say for 1, 2, 3 and 4 minutes. Continue with the rest of your processing and when dry examine the tests using a very bright light. There should be no difference at all in color between the area that was coated and uncoated.

    BTW, I did not really understand what you mean by gold tioned platinotype? Are you making kallitypes or Pt./Pd. prints? Or is platinotype the paper?

    Sandy
     
  3. philsweeney

    philsweeney Member

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    I am making kallitypes and yes the paper is platinotype.
     
  4. sanking

    sanking Member

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    OK, then I think it is perfectly acceptable to decrease the time of clearing if your paper looks clear, subject to resuslts from the test discussed earlier. I generally tone with palladium and do not see any loss of density with a total clearing time of 4 minutes with 3% citric acid. You could also decrease the strength of the solution to 1.5% or 2%.

    Combining sodium citrate with citric acid would result in a less aggressive clearer. The clearing agent must be acidic to work. A 25% solution of sodium citrate has a pH of about 7.5, a 3% solution of citric acid is about pH 2.5. If you combine equal parts of the two the resulting pH is about 6, still very acidic.

    Sandy
     
  5. philsweeney

    philsweeney Member

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    I have been comparing gold toning to the palladium toning. The gold does not seem to do as well. I processed one print with no clearing and gold toner, and the result is poor compared to palladium toning. I am going to stick with the palladium toner and longer clearing times. Though I want to experiment with the split toning a little. Thanks!