Re: Albumen toning questions/Polytoner

[Richard Knoppow <dickburk@ix.netcom.com>]

At 12:18 AM 05/29/2002 -0400, you wrote:
>
>On Tue, 28 May 2002, Richard Knoppow wrote:
>
>> At 04:34 PM 05/28/2002 -0400, you wrote:
>> >I understand that Kodak's long running Polytoner-- which I use regularly--
>> >has been discontinued. Arthur
>> >
>>   Polytoner is gone and Agfa Viradon, which used to be a similar
>> combination sulfide and selenium toner, no longer has selenium in it.
>>   However, you can make what is essentially Kodak Polytoner from Kodak
>> Brown Toner and Kodak Rapid Selenium Toner.
>
>
>My inclination would be to use the "liver of sulfur" formula from
>Photographic Facts and Formulas... that's sulfurated potash (so called to
>be quaint, but actually potassium sulfide), available several places
>including Tri-Ess.  My *memory* is that that's supposed to be more
>archival than selenium, and since they're bound to discontinue the other
>toners as well... why have to switch again?
>
>I also would not if possible to avoid use Kodak brown toner -- that's the
>REALLY REALLY stinky one (sodium sulfide), n'est-ce pas?  Why not use
>thiocarbamide?
>
>Judy
>
  Kodak Brown Toner, and current Agfa Viradon are Polysulfide toners.
Kodak formula T-8 is for a similar, but less concentrated polysulfide
toner. According to Doug Nishimura both KBT and T-8 are suitable for
archival toning. 
  In fact, the ability of a polysulfide toner to tone highlights and
shadows evenly is related to the concentration of the stock formula. This
has an effect on the complexity of the sulfide ions in the toner. The more
concentrated the better. 
  The Image Permanence Institute developed a polysulfide toner for use on
microfilm wich is essentially odor free. It uses borax rather than
carbonate. I've posted the formula and method of mixing to the Pure-Silver
list, it should be in their archives. If this list wants it I will repost
it here. I have no idea of its color on printing paper or alternative
processes prints. 
 The problem that IPI discovered with Kodak Rapid Selenium Toner was that
it was not toning the low density parts of the images enough to protect
them. In the past evidently KRST was also causing some sulfiding of the
image which was sufficient to protect the areas the selenium wasn't
getting. If an image is toned sufficiently in KRST it is as permanent as a
sulfided image. The toning of microfilm has some special problems because
its desireable that the image structure not be changed by the toner.
Selenium works well for this. Its not an issue for pictorial work so
greater toning is permissible. 
  Doug Nishimura, of IPI, recommends that prints and films be toned in KRST
diluted no more than 1:9 for three minutes minimum at 68F. The resulting
Silver selenide is as stable as Silver sulfide.
  KBT will also provide good image protection to both film and prints. 
  The IPI toner works at room temperature which is a convenience and
probably contributes the its low odor. 
  For reference here is Kodak T-8

Water						750.0 ml
Liver of Sulfur				  7.5 grams
Sodium Carbonate, dessicated		  2.0 grams
Water to make 				  1.0 liter

Use full strength. The toner takes about 15 to 25 minutes at room
temperature. Toning is substantially accelerated when heated to 100F. 
  After toning rinse for a couple of minutes in a 10% Sodium Sulfite
solution to prevent further toning in the wash. 
  Polysulfide toners have the peculiar property of toning faster as they
are exhausted or diluted. If too diluted (which can happen if washed out
too slowly) a peach colored stain may appear in the highlights. 
 Its important not to overwash silver images. A small amount of thiosulfate
remaining in the emulsion causes a slight sulfiding which provides
considerable protection against oxidation of the silver. In their paper on
toner protection Kodak Labs found that image stability even after using
KRST was better for emulsions with some thiosulfate left in them. I am
slightly puzzled by this since KRST itself has considerable Ammonium
Thiosulfate in it. Perhaps not enough to be effective at the 1:20 dilution
used in the experiments. 
  This may be OT for alternative processing except that negative permanence
is still of interest and the anti-oxidation properties may be desirable in
processes which result in metallic silver images. 
----
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com