clearing pt/pd

Judy Seigel (jseigel@panix.com)
Wed, 23 Aug 1995 14:04:47 -0400 (EDT)

On Wed, 23 Aug 1995, Beakman wrote:
> I use Kodak Hypo Clearing Agent (HCA). I am printing on Arches Platine -
> 2 coats which I allow to dry overnight. Needless to say, the iron has a
> tenacious grip on this paper and serious clearing is required. HCA is
> made up of sodium sulfite, sodium metabisulfite, sodium citrate, and
> EDTA, so it is really a convenient combination of several popular
> clearing agents.

Well, as we say on the farm, live and learn!

Of course the question that immediately arises (a favorite on this list)
is which is the BEST clearing agent. We are told that platinum,
platinum/palladium and plain palladium clear differently. (Maybe
developer & paper enter the equation, too.) How to decide?

I gather there is no test for residual iron, other than waiting 100 years
to see how it turns out. With kallitype I tended to assume that if the
paper LOOKED clear, with no yellowish stain, it WAS clear (& as I
mentioned, sometimes this happened with no clearing beyond the developer).
But maybe harmful residue could be colorless -- at first?

Or maybe there IS a test for residual iron , or could be......??????

Judy