RE: New Cyanotype

Rick,

For what it is worth my experiences with traditional cyanotype formula
parallels your description below. I use a citric acid wash using tap water
as well, I'm surprised that no one else has mentioned using and acid
clearing bath. I'm also curious what the effect of soaking some marginal
papers with oxalic acid may have on the quality of the print.

Also in the FWIW department, my very first trial of cyanotype printing
several years ago resulted in a very pale print, as almost all of the blue
went down the drain. I was using Canson Bristol watercolor paper (some of
which I still have) so I suspect that problems with bleeding cyanotype are
paper related. I should dig out the paper and test it again with the new and
old cyanotype.

I like the Ware formula also, it seems to give better separation in the
darker tones and holds detail in the highlight areas too, but the tonal
scale seems to be compressed when compared to prints made with the
traditional formula. At one time I had pondered using both formulas to coat
the same piece of paper but I've never tried that, after reflecting on it a
while though I think there would be little to gain doing this.
 
Since were are discussing cyanotypes today I might also mention that I just
received today several cyanotype prints made on fabric from Diana Bloomfield
for inclusion in the Alternative Process Traveling Portfolio. One of the
pieces sent by Diana was toned in borax and tannic acid which produced deep
navy blues, a very handsome print. Unfortunately she failed to mount her
prints ;-).

Don Bryant

>
> Boy, now I'm paranoid. Here I was, happily using my water from the tap
> without thinking too much about it. I must be lucky. I do get quite
> consistent results with a very high maximum density (bordering on black).
> I
> do use the citric acid (approximately 2% solution) as a preliminary wash.
> I
> do get a lot of blue in that wash water and I normally don't use it for
> more
> than four or five prints (12 by 18 in.)
>
> I expose until the shadows are white and the medium tones are slightly
> reversed. I use a very dense negative.
>
> Anyway, that is my two cents.
> Regards, Rick Retzlaff
>
> -----Original Message-----
> From: Ryuji Suzuki [mailto:rs@silvergrain.org]
> Sent: Thursday, May 20, 2004 2:11 AM
> To: alt-photo-process-l@sask.usask.ca
> Subject: Re: New Cyanotype
>
>
> From: "Gordon J. Holtslander" <holtsg@duke.usask.ca>
> Subject: Re: New Cyanotype
> Date: Wed, 19 May 2004 23:15:12 -0600
>
> > I've always suspected thay cyanotype is very sensitive to the pH of
> paper.
> > Is there a standard way of checing the pH of paper. I don't have a pH
> > meter, but I have plenty of litmus paper.
>
> It's sensitive to the pH of the coated layer, that is very likely.
> For primary photochemical stage of cyanotype-type reaction, see
>
> Abrahamson, H. B., Rezvani, A. B, and Brushmiller, J. G. 1994.
> Photochemical and spectroscopic studies of complexes, of iron(III)
> with citric acid and other carboxylic acids. Inorganica Chimica Acta,
> Volume 226, pp. 117--127.
>
> On top of this, you have the issue of ammonium ion from the ferric
> ammonium citrate, and also the pH dependency of the secondary process
> to form Prussian blue. My guess is that the optimal pH is shifted or
> widened upward. If I were a regular cyanotype printer, I'd do a couple
> of hours of search for a good buffering system that doesn't interfere
> with the process, and use it. (That's probably just me. I hate
> mysteries and I don't like continual attention for the too many little
> things during ongoing work...) But guessing from the fact that this is
> not customarily done, there is some technical difficulty that I don't
> know about?
>
> About the measurement of pH of paper, according to my paper reference,
> there's such thing as ISO6588:1981, and other standards, but I don't
> know much more.
>
> --
> Ryuji Suzuki
> "You have to realize that junk is not the problem in and of itself.
> Junk is the symptom, not the problem."
> (Bob Dylan 1971; source: No Direction Home by Robert Shelton)
Received on Thu May 20 21:11:18 2004