Re: Blues to die for

Philip Jackson (pjackson@nla.gov.au)
Tue, 15 Oct 96 13:35:00 PDT

So this staining isn't just my problem after all! The test strip was fine,
but larger prints weren't, suggesting maybe the amount of water reserve in
the tray is a factor (presumably with only a small amount the Prussian blue
particles washed off are fairly concentrated and more prone to stain the
highlights). Anyway, I fixed it by pouring a small amount of the citric acid
wash water on the paper a little at a time, draining and replacing every
minute or so. A flat bottomed tray (the meat marinade container I got at
Big-W or K-mart) used this way requires much less wash water than the
traditional grooved bottom photographic tray.

>However mine was on different paper, and with a different cyanotype
>formula (plain old ferric ammonium citrate & potassium ferricyanide) and
>presumably that is an important difference.
>
>Meanwhile, it occurs to me to wonder if the "regular" formula on the same
>paper without the citric acid wash would be darker or lighter than your
>formula (is that Mike Ware's new cyanotype you're using?) with the citric
>acid wash...... tho of course, this way lies madness......

My test did indeed use Mike Ware's new cyanotype formula (2 not 20 min.
exposure!) The citric acid wash might not make such a difference with the
"old" cyanotype formula; and paper may also be a significant factor. I still
have some very old standard cyanotype sensitizer but won't be able to try
this till I get back. No big deal, youv'e got to be a little mad anyways...

Cyantifically yours (to steal your by-line),
Philip Jackson