"Lew" wrote in message
news
I usually tone my negatives in dilute (1:30) KRST, but I've
never done this with my films developed in PMK. I can't
think of any reason why I shouldn't, since I believe that
the KRST has a positive ph & shouldn't detract from the
stain. Any other opinions?

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-Lew

Selenium or a sulfiding toner will tone the silver but
not the stain. Actually, the stain image is a pigment and
very permenant. Kodak Rapid Selenium Toner is probably about
neutral pH, it is certainly not acid.
Note that diluted KRST is no longer considered an
adequate toner for preserving film. A better toner is Kodak
Brown Toner. KBT tones all densities evenly so partial
toning will provide protection to all parts of the image.
KBT is quite alkaline. While KBT tones prints brown or sepia
it may result in a slight cooling of image color of some
negative emulsions. KBT or some other form of Polysulfide
toner, is now the recommended method of protecting
microfilm.


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Richard Knoppow
Los Angeles, CA, USA