RE: Gums a la Demachy and Puyo and all sorts of other things including cyanotypes

Terry,

________________________________

From: TERRYAKING@aol.com [mailto:TERRYAKING@aol.com]
Sent: 17 Temmuz 2006 Pazartesi 17:42
To: alt-photo-process-l@usask.ca
Subject: Re: Gums a la Demachy and Puyo and all sorts of other things
including cyanotypes

Loris

>"The 'classic' cyanotype, which is a relatively modern introduction, is
simple cheap and easy. You can get a high d max with one coat if you use the
right negative."

Double wrong (in Newspeak)... Price per print is about the same with both
processes ($30 per kg) and the other emulsion component is same for each.
Won't go again with the dmax issue - see our first correspondance on the
issue months ago... (Dmax was tested without a negative, simply the dmax of
new cyanotype was better for exposure times that give dmax with each
processes - tested before with step tablets)

>"As to the 'new cyanotype' ,as you say yourself, the 'new cyanotype' uses
uncommon chemicals which are more difficult to mix and you have to use
special methods to coat the paper."

Ammonium Iron(III) Citrate is as uncommon as Ammonium Iron(III) Oxalate! For
instance, you can't order Ammonium Iron(III) Citrate from Merck (one of the
biggest suppliers) - they even weren't listing it in their catalogue when I
was looking for AFC 3 years ago - whereas Ammonium Iron(III) Oxalate is
listed (and still is) and can be ordered from them (or any other important
chemicals suppliers).

>"Loris, have you noticed that the appearance of gum prints tends to be
somewhat different from that of cyanotypes? It is that difference which
justifies the complication."

Bullseye! Same to me between Cyanotypes. (And the price / emulsion
preparation procedure / whatever else differences are not as deep as the
ones between gums and inkjet prints - not even close to it!)...

>"..."

>"Your comment

'New Cyanotype is easier to coat because paper
absorbs the sensitizer more easily; I never had grainy results with New
Cyanotype (had grainness with some of my Classic Cyanotypes - I don't have
problems with coating Classic Cyanotype BTW, New Cyanotype is just easier).'

leads one to believe that you have not got your technique quite right. You
should not be having to think in terms of the differences in the absorbency
of the paper for the two processes. If you are applying the 'classic'
cyanotype correctly, you should not be getting any graininess. Graininess
implies that you are putting too much solution on the paper."

Read well; I'm very able to coat each processes - I was successful in
applying the classic emulsion with papers that gave grainness later, by
using "complicated" (in your words) measures like addition of surfactant to
the emulsion and/or changing brushes/using glass coating rods ect. Why
bothering since I have a better emulsion (in the terms that we're
discussing: ease, cost, dmax, exposure times) on hands?

Loris.
Received on 07/17/06-02:05:26 PM Z