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  1. #1
    Davec101's Avatar
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    Acidifying and De-acidifying paper for platinum printing

    Posted this on my blog thought i would put this on here to see what others thought.

    'A common practice by contemporary platinum printers is to acidify certain watercolour/printmaking papers to prevent an acid-base reaction commonly observed when an acid ferric oxalate solution reacts with an alkaline paper surface. The process of acidification is simple and involves soaking the paper in either citric acid or oxalic acid for a certain period of time ranging from 1-15 mins. Usually this not only makes a paper useable for platinum/palladium printing but can lead to a dmax increase of up to .20. Each batch of paper can vary so its important to take regular tests to insure consistent results. Many papers I edition with require acidification and it has become a regular part of my workflow. The process can remove the internal sizing of certain papers and may require the use of a hot press to flatten after the print has dried.

    Recently I came across some notes written on the back of a Penn Platinum print that mentioned the process of deacification, which I had not encounted before. The print entitled ‘Sitting Nude Rear’ shown below was printed in June 1994 on BFK Rives and went through 3 platinum/palladium coatings and exposure cycles. The full details are shown below the print

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    “SITTING NUDE REAR / (NEW YORK, 1993) [in a box]”; stamped and inscribed verso: “HAND COATED BY / THE PHOTOGRAPHER / IP:”; stamped verso: “Deacidified”; inscribed verso: “RIVES PAPER ON ALUMINUM / MULTIPLE COATING AND PRINTING / 1 [in a circle] PLATINUM-PALLADIUM / 2 [in a circle] PLATINUM-PALLADIUM / 3 [in a circle] PLATINUM-PALLADIUM”; inscribed verso: “3/6”; stamped verso: “PHOTOGRAPH BY IRVING PENN / “Print made June 1994”; stamped and inscribed verso:

    The process of deacification, as the name suggests, would involve removing the acid from a particular paper, this is the opposite of what contemporary platinum/palladium printers are doing today as previously mentioned above. It would be interesting to learn more about this from other printers, I would have thought BFK Rives in 1994 would have been acid free and would require acidification, but it would seem that this is not the case in this instance.
    Last edited by Davec101; 03-03-2012 at 04:17 AM. Click to view previous post history.
    Platinum Printing Editions http://www.dceditions.com
    The Art of Platinum Printing Blog http://artofplatinum.wordpress.com/
    Alternative Photographic Processes blog http://altphotoblog.com/

  2. #2
    payral's Avatar
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    Don't you think it could be Deacidified once print made just to bring it to neutral state for long time conservation.

  3. #3
    Davec101's Avatar
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    Quote Originally Posted by payral View Post
    Don't you think it could be Deacidified once print made just to bring it to neutral state for long time conservation.
    I think thats got to be the most likely explanation Philippe. Purhaps he was using one of the modern chelating agents such disodium and tetrasodium Edta as a clearing bath to bring print to a more neutral state and was making note of this on the back to give museum's and conservators etc.. this additional information. I would imagine after three successive coatings and exposure cycles the print would have been in a heavily acidic state and would require quite lengthy deacification. I know from my own research that multi-layered platinum/palladium prints can take significantly more time to clear compleatly when compared to those of a single layer.
    Last edited by Davec101; 03-03-2012 at 02:58 AM. Click to view previous post history.
    Platinum Printing Editions http://www.dceditions.com
    The Art of Platinum Printing Blog http://artofplatinum.wordpress.com/
    Alternative Photographic Processes blog http://altphotoblog.com/

  4. #4

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    Ditto. +1 from here...

    P.S. The print, image and the rear are all gorgeous BTW!

    Quote Originally Posted by payral View Post
    Don't you think it could be Deacidified once print made just to bring it to neutral state for long time conservation.



 

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