RE: cyanotype

Hi Christina,

I absolutely don't know what's the water solubility figure of FAC. All I
know is that Traditional Cyanotype doesn't soak as easily as New
Cyanotype or Ziatype emulsion. You can tell that by observing the paper
after coating; the shine on the paper dissappear in a relatively longer
time. The crystallization I'm talking leaves tiny white spots (not
fibers) on the paper, in some cases I found bits of emulsion that were
stuck to the negative. IME, too much emulsion is a real problem with
Cyanotype. Thinking that way, I habituated my self using as little as
possible emulsion when doing traditional cyanotypes - so little that my
students had hard time - in their first trials - to coat a given area
with a given amount of emulsion (I wasn't having problems in the same
conditions). Some never managed to coat properly - without leaving
uncoated parts in the image area - with that specific ml to inch2 ratio,
so I had to increase the ratio to suit their coating style / speed.

Regards,
Loris.

-----Original Message-----
From: Christina Z. Anderson [mailto:zphoto@montana.net]
Sent: 15 Şubat 2006 Çarşamba 17:55
To: Alt List
Subject: Re: cyanotype

...
Loris said: with Traditional Cyanotype I had to coat the
paper twice. This was a real problem since there was 2x the risk of
abrading the paper (I can be pretty heavy-handed being a large person -
220lb, 6.22' - have ruined quite a lot papers while double coating...),
also "in my practice" traditional formula is more prone to
crystallization on paper "especially when double coating" (absolutely no
good for the sake of the image and the negative).

Question: which leads back to Michael, I think, who asked instead of
using 20% FAC 2 parts to 8% potassium ferricyanide 1 part, why not mix a
40% solution of FAC and then use that 1:1 with an 8% solution of
potassium ferricyanide...I wondered if mixing it up that heavily would
lead to undissolved FAC in solution, if there is a point where FAC falls
out of suspension....and then might lead to graininess or some such
thing. You say, below, you get crystallization on the paper--do you mean
white spots, actual crystals, graininess, etc??? Short of just mixing
up a 40% and trying it myself, which I might do, I'm just wondering if
graininess that people complain about with the traditional formula has
to do with too much FAC...OR even, if the amount of FAC doesn't even
matter that much as one person has suggested.
...
Received on Wed Feb 15 15:12:54 2006