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Thread: Cyanotypes

  1. #11
    John_Brewer's Avatar
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    Hi Kai

    Could you elaborate on your toning methods with tannic and gallic acids. What alkali do you use to hydrolyse the cyanotype? How do you use the acids? Do you use the traditional or the Ware recipe? The images of yours at http://www.fotocommunity.de/pc/pc/display/1985944 show a nice variation of colours. My only experimentation has involved hydrolysing with ammonia and redeveloping in tea or tannin. In both occassions the paper badly stained and the dmax was much lower than the original cyanotype resulting in a low contrast muddy print.

    Regards

    J
    ~John~
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  2. #12
    Gustavo_Castilla's Avatar
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    I have and I think I preferd the A+B better and Ilike even more the cyanotype Rex and
    the Chrysotype Rex method easyer to comtrol and well they all are beatiful
    Gustavo Castilla
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  3. #13
    Ole
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    Quote Originally Posted by John_Brewer
    My only experimentation has involved hydrolysing with ammonia and redeveloping in tea or tannin. In both occassions the paper badly stained and the dmax was much lower than the original cyanotype resulting in a low contrast muddy print.
    My own attempts at toning cyanotypes have been with tea, no alkali. Since my tapwater is slightly acidic, there was no loss of Dmax but rather a strong gain! The shadows changed from blue to a deep bluish-black, with highlights grading through a pinkish tone to almost pure white. If your teawater is alkaline, add a little citric acid - "tea with lemon". No bleach first, and watch the print deepen...
    -- Ole Tjugen, Luddite Elitist
    Norway

  4. #14

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    Ole, you can actually watch the tones deepen when you tone with tea? It takes me an hour to get a visible difference. I would yank it after two, because after that the tea starts to stain the paper.

  5. #15

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    Quote Originally Posted by Gustavo_Castilla
    I have and I think I preferd the A+B better and Ilike even more the cyanotype Rex and
    the Chrysotype Rex method easyer to comtrol and well they all are beatiful
    How does the Cyanotype Rex method work? I can't find any description online, just glancing references.

  6. #16
    Ole
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    Quote Originally Posted by psvensson
    Ole, you can actually watch the tones deepen when you tone with tea? It takes me an hour to get a visible difference. I would yank it after two, because after that the tea starts to stain the paper.
    I get a visible difference in about five minutes, and tone for max. 30 minutes. Lipton Yellow, 2 bags in 1/2 liter hot water. Steep until bitter and luke-warm.
    -- Ole Tjugen, Luddite Elitist
    Norway

  7. #17

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    Hi John,

    ammonia is fine because it works gentle. Other chemicals I´ve tried are sodium carbonate, sodium hydrogen carbonate, potassium hydroxyde and some others with different success. Seems that ph control is the key. Simply said I think the alkaline chemical is not only forming the ferric hydroxyde from prussian blue but is also something like a starter and catalyst for tannic/gallic acid toning.

    The last times I´ve immersed the dry cyanotype in slightly acidified water (1,5% acetic acid) for 2 minutes, then after a short wash in plain water bleached them in lye like a 1% ammonia bath. Then again a short wash and back into the acidified water to neutralise or wash out most of the lye near the surface (If not all prussian blue was transformed there is a blue/yellow split at this stage or some blue reappears in all tonal ranges. That´s not bad at all if one is heading for a near neutral black because the blue adds up with the brown of the toned print). After a short wash the bleached cyanotyes are toned for some minutes in a strong tannic/gallic acid bath (about 1%) made with a pinch of sodium carbonate and hot water which helps to disolve the tannic/gallic acid. For stopping the toning as fast as possible I pop the cyanotype directly back in the acetic acid bath for five minutes and wash at last with tap water. It may sound a little bit complicated but works pretty good for me. Gallic acid is much more prone to staining than tannic acid and the toned cyanotypes have a less redish color tone.

    If you want to keep it simple try an acetic acid stop bath after toning to neutralize the base in the paper fibers to prevent staining. I think base=activate and speed up toning, acid=slow down or stop toning is a simple rule that I have to examine closer. Maybe I should buy an electronic ph meter for exact data -- ph teststrips are ar pain to work with and not acurate enough.

    All the best
    Kai

    PS: The toning procedure described is only one of a lot worth to consider. Another one I really like one tray toning because it is so simple and creative. And I don´t use the Ware recipe. My brews are more conventional and in memory of John Herschel I´m fond of brown ferric amonium citrate right now =:)
    Last edited by Kai Hamann; 08-22-2005 at 03:11 PM. Click to view previous post history.

  8. #18
    John_Brewer's Avatar
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    Thanks for your detailed response Kai. I shall give it a go.

    J
    ~John~
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    There are 10 types of people in this world - those who understand binary and those who don't.

  9. #19
    Gustavo_Castilla's Avatar
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    is so simple you will kick your self first credit where credit is do
    It is credit to Terry King (TERRYAKING@aol.com) Terry King FRPS

    RPS Historical Group (Chairman)

    www.hands-on-pictures.com/
    I will finish this a bit latter
    thanks
    Gustavo Castilla
    We are not moved by things ,
    but by the views we take of them.
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  10. #20
    Gustavo_Castilla's Avatar
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    o.k. first you coat the paper with Ferric oxalate Only add a gram or two of oxalic acid (If you have a 500 ml of ferric oxalate, add 25g of oxalic acid) to the solution. to the solution let it dry and then develop on a solution of .05% to 5% of of potassium ferracyanidine
    Gustavo Castilla
    We are not moved by things ,
    but by the views we take of them.
    Epictitus.
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