Re: Toning kallitypes and vandykes

Toning kallitypes and vandykes...what was the percentage of replacement after 20 minutes, if you don't mind me asking? 50? More than 80? Close to 100?

~m
  ----- Original Message -----
  From: Sandy King
  To: alt-photo-process-l@sask.usask.ca
  Sent: Sunday, November 13, 2005 10:26 PM
  Subject: Toning kallitypes and vandykes

  I posted the following message over on apug.org but so far have gotten zero response. Hope someone here can offer some advice.

  Basically the situation is this. I interested the folks in photographic conservation at the Getty with the issue of toning kallitypes with pallaidum and platinum, specifically. Preliminary spectra analyis in their lab has confirmed that toning a kallitype (and I believe the same would apply to vandyke) with palladium or platinum results in replacement of the silver by the more noble metal, adding much permanence to the print.

  The toning formula used for the tests was 5 grams of 20% palladium chloride solution plus 5 grams of citric acid in one liter of water, and I did toned 5X7 test samples for 2.5, 5, 10 and 20 minutes, using just enough of the toner to cover the surface of the print in flat bottom tray. That turns out to be about 50ml of solution for a 5X7" print.

  What the tests showed was that the efficiency of toning in terms of the percentage of replacement of the silver with palladium is time dependent, i.e. a toning time of 20 minute results in a much higher percentage of replacement than toning for 5 minutes. This leads me to a question that I hope some of the chemists on the list might be able to answer. Does anyone have any idea how I might adjust the toning formula formula above to make it faster acting?

  Sandy
Received on Mon Nov 14 00:01:20 2005