Re: When to tone?

From: mmatusz@pdq.net
Subject: Re: When to tone?
Date: Thu, 13 Nov 2003 08:58:29 -0600 (CST)

> I had the same problem with a home made liquid emulsion. As best as I
> could tell this relates to incomplete washing of thiosulfate. Brown stain
> was always stronger when the emulsion was thicker. I ended up washing
> prints for a very long time before toning. Perhaps the use of a basic
> fixer (like photographers formulary TF4) instead of standard fixer would
> help. I would also try Mr. Suzuki's suggestion of a basic wash (sodium
> carbonate solution) after fixing. I know the pain, a perfectly good print
> goes into the toning bath and comes out a disaster.

Like I said in another posting, insufficient fixing is my number one
suspect. Ammonium thiosulfate fixing bath adjusted for neutral or
slightly alkaline pH is most effective, and they washes a bit faster
than regular fixers.

You said "perfectly good print goes into the toning bath and comes out
a disaster" but I find this a bit deceptive. Because prints that are
insufficiently fixed (or washed) will deteriorate in the future and I
would throw them away rather than keep or sell. The easiest way to
figure out if the print is adequately fixed is to tone the print,
because toner would react with unfixed yellow-white silver halide
crystals to form dark silver compounds.

--
Ryuji Suzuki
"Reality has always had too many heads." (Bob Dylan, Cold Irons Bound, 1997)