I’ve been doing a deep dive into alternative processes with QTR and recently started testing
Mike Ware’s New Cyanotype, using the
premixed solution from Bostick & Sullivan to eliminate mixing variables.
Setup:
- HPR paper
- Tween + citric acid added at 1 drop/ml just before coating
- Coastal San Diego, ~60%+ humidity (no paper humidification)
- Citric acid added to first wash
- LED UV exposure unit, 3-minute exposures
- Exposure calibrated with a Stouffer 31-step wedge
Despite dialing in exposure carefully, I ran into
major fogging issues.
After speaking with B&S, I learned that citric acid had been added to the
bulk premixed solution. This destabilizes Ware’s NC and shortens shelf life — citric acid should
only be added
just before coating.
I ordered a fresh bottle after accidentally leaving my original solution uncapped for several days. Unfortunately, the new shipment
leaked in transit. With the new solution, things got much worse:
- Heavy fogging
- No clean whites
- Even an unexposed, developed strip turned light blue
Since I was working under safelights (and NC is usually safe under dim incandescent light anyway), light exposure wasn’t the culprit.
I then poured samples of both the old and new solutions into cups to compare color. The difference was obvious — the
new solution was significantly darker. The fogging was clearly coming from the solution itself (see photo).
I spoke with
Dana at B&S, and he’s remixing a replacement
without citric acid. I’m hoping that resolves the issue — otherwise, I may be done with Ware’s New Cyanotype.
Photos below:
- Stouffer 31-step wedge — old solution, no fogging.
- QTR Blocking Density Target — fogged, no whites (new solution)
- Unexposed strip, developed — light blue (new solution)
- Side-by-side solution color comparison