> I'm well aware of this, and one reason I'm on this list. However I wasn't
> aware that the Kallitype was "as good" in image quality as a platinum
> print. I figured it may be good but not that good.
I think we're confusing some terms here -- there's a process generally
called van dyke brown (VDB), in which silver nitrate, ferric ammonium
citrate and tartaric (or other) acid are mixed. Development is in water,
followed by fixer, no "clearing bath" necessary, just hypoclear (if
desired) and wash. But this is also called kallitype in some places and by
some people. It is however, nearly as simply as cyanotype -- only the
fixing step is extra.
Then there's a process called at the time it was evolved to substitute for
platinum when platinum got very expensive (the Ferro-Prussic war, or
something, circa 1917) *kallitype*, which is the subject of Dick Stevens's
(problematic, but I've dwelt on that elsewhere) book. This process, which
more or less substitutes silver for platinum, using ferric oxalate for
developer, developing in various chemicals from B&S ammonium citrate to
your own heavy mix of Rochelle salts (I found sodium acetate best), and
with clearing bath as well as fixing bath and hypoclear required, is
therefore much more laborious than VDB, tho with more flexibility in color
and contrast range. It is however, according to Mike Ware, *less*
archival than VDB. Many people, in addition, found it difficult &
temperamental (which I did not), hence Stevens's book.
Four more points:
A student of mine a couple of years ago did a pd/pl print and VDB print
from same negative, each with a 21-step. The VDB had *at least* as
beautiful gradation as the pd/pl, only color was browner.
VDB doesn't have the same contrast controls as kallitype, is best
controlled by matching negative to the paper. I don't know about
Argyrotype in this respect, tho it has some color control by
pre-humidifying for a purplier cast.
Argyrotype was formulated, I believe, to replace VDB, and is on that order
of simplicity.
There is a ***great deal*** about kallitype in the archive, circa fall
'95, but then I think I said that.
Judy