From: WLINNE (isabella32@earthlink.net)
Date: 05/09/00-11:29:49 AM Z
Hello,
Please excuse my ignorance of chemistry, but wouldn't putting a
cyanotype through an acid bath adversely affect the permanence of the
image? I thought the point was to avoid acid in the paper as much as
possible.
curiously,
William
Adam Kimball wrote:
>
> Hey all,
>
> I'm still reading, just not posting not lately. I've been
> doing a lot of New Cyanotype work this last six months.
> I've done quite a number of variations with the acid
> developers, and here is what I know.
>
> Nitric Acid - very dilute (between .5% and 1.5% in my tests)
> - the benefit of Nitric is that the "solarization" from
> overexposure is remedied quite quickly - allowing you to
> step the skip of using a dilute hydrogen peroxide bath if
> you want to see the results instantly.
>
> Hydrochloric - at a similar dilution. Acts similarly, but
> doesn't help much with the solarization.
>
> Citric - my favorite. Mike told me that there is some
> chance that the image may fade if left in strong light for
> long periods AND is wash insufficiently. The fading is not
> permanent though, he says, and can be fixed by putting the
> print in a dark space for a day or two where it has some
> exposure to oxygen (i.e. not a drawer).
>
> I've also experimented with adding tiny amounts of Ammonium
> Dichromate for contrast control. I've used drops of .25,
> .5, .75% in 1ml of sensitizer and it seems to help getting
> more contrast. Varying the acid concentration is another
> variable.
>
> My only real advice, however, is coat carefully, dry
> thorough, and wash thoroughly. Too much sensitizer will
> result in a terrible blotchiness, so use the least possible.
>
> Hope that helps,
> Adam
>
> Judy Seigel wrote:
>
> > Maylee, I was hoping someone else would answer that... My thought is that
> > since hydrochloric is (I believe) the one used with the New Cyano, maybe
> > try that. But then again, if you don't have any, I think citric would show
> > the effect -- tho it's been suggested that it isn't as archival in
> > results.
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