old vs. new cyanotype

A while back we were discussing the two cyanotype formulas. I reported this
weird thing happening with the new cyanotype: the print would look perfect
but all highlights would be lavender. I thought my solution was fogged, so I
ordered a new batch from Photographer's Formulary.

I mixed up the solution yesterday. I do say it is way more work to mix than
the traditional formula, but still, manageable. The Formulary kit is so
wonderful because everything is measured out in packets for you. $20 for
100ml.

You have to heat distilled water, add the green crystals of ferric ammonium
oxalate, pour in the bottle of dichromate solution, and then (the only putzy
step) grind up the potassium ferricyanide crystals to a yellow powder. This
I do by leaving it in the bag it comes in, and rolling it with a rolling
pin. No mess, no dust. Then you have to add this to the mix and let sit in
the dark for an hour. Then pour it thru a coffee filter and add water to
make 100ml. Not bad, but still, one vote pro traditional.

My old (very) solution was not fogged, because I still got the lavender
highlights. I figured out what it is, too. Luckily I was making salsa.
Not having my photo chemicals here, I squeezed some lime juice onto the
lavender highlights and presto, they turned blue. Thus, the lavender is
exposure, but in an alkaline environment. I feel like the Martha Stuart of
kitchen photography.

Hence, Fabriano Artistico is probably not a suitable paper for the new
cyanotype unless you dink around somehow. I tried coating it with oxalic
acid before printing, and that did not work. One more vote for the
traditional.

Other than this, still no wash off, still deep blue, still looks perfectly
fine under tricolor gum, because the acidity of the dichromate in the gum
layers must do what the lime juice did, takes care of the lavender.
Chris
PS BTW, Tom Ferguson, even with the paler nickel titanate layer in the Wang
process, as opposed to the cadmium yellow, I still did not need to reprint a
yellow layer--it was plenty yellow.
Received on Fri Jun 11 08:18:02 2004