Re: Indirect toning with KRST

From: Liam Lawless <liam.lawless@blueyonder.co.uk>
Subject: RE: Indirect toning with KRST
Date: Fri, 26 Mar 2004 04:28:55 +0000

> I used to do some strange things with selenium, but for straight toning
> it was fairly similar to KRST as far as I remember. But one major
> difference - and the main reason I stopped using it - is that its
> behaviour on Ilford Warmtone, a paper I use a lot, is very different.
> T-55 at the normal 1+5 dilution had no visible effect until 25 or 30
> minutes, when it would suddenly turn a bright purple-pink in a very
> short space of time. I didn't like this pink, whereas KRST works
> rapidly on Ilford WT and gives colours that I do like, plus split tones
> if you want them.

Ok, I hate to say this but I need to say. There are at least two
different kinds of warmtone enlarging paper emulsions. One is classic
chlorobromide emulsion of very small grain size. These are the type of
warmtone emulsion you want to use for toning and lith printing. These
are very slow. Forte Fortezo is an example of these in current
production, and I love it so much but that paper curls so badly when
drying and that is the seriously annoying problem.

Another type, most likely including the Ilford Warmtone is regular
chlorobromide or bromide paper that is otherwise cold tone, but has an
tone modifying agent that makes the image warm toned when processed in
conventional chemistry. There are lots of such compounds known in the
literature and I don't know exactly how they work. (I think the
inventors don't even know.) These emulsions are absolutely unsuitable
for lith printing, and may or may not work with toning depending on
the chemistry, but more likely to result in disappointing hue shift.
If the hue of straight prints is warmer than most other papers of
the comparable speed, suspect this...

--
Ryuji Suzuki
"All the truth in the world adds up to one big lie." (Bob Dylan 2000)