My cyanotypes take forever to expose when I use either stained or reasonably dense negatives, so I'm thinking of getting that $20 New Cyanotype kit from Photographer's Formulary. Is it easy to mix up and use? The Christopher James book about alt processes makes it seem like you need to work in a chemistry lab to make it up.
I have also found that pyro and stained negs sometimes wont even allow an exposure with cyanotypes. Only a nearly perfect pyro neg will yield an exposure, and those cyano's are usually astounding.
Many cyano formulas are highly dependant on the paper you are using, and the ratio of feric amonium citrate to potassium ferricynide (pfc). This is how I make cyano's and they come out great.
1)I use Weston Diploma parchment, it costs more up front, but is cheaper per sheet then Arches and Fabriano.
2) create a 1:1 mixture of pfc solution and feric amonium citrate solution.
3)double coating my paper ( coat, dry, coat, dry). This creates deeper blues.
4) expose for 15-20 minutes (arizona sun).
5) before washing coat it with PFC. PFC is the developing agent and doing this will allow you to achieve deeper blues and more midtones.
Ferric ammonium citrate is the light sensative component, and PFC is the developer. If you play around with the ratios, coating, and paper you will find your magic combo. Switching papers in the middle of expirmentation will void all previous tests, unless of course the paper is your control. Try to buy paper in large quantities, because manfacturers change their papers on a whim and without notice.
The "New Cyano" substitues Oxallic acid for one of the chemicals in the original formula, but im not sure which one.
Clear as mud. I know.
I actually did an all-night exposure using three 15-watt blacklight bulbs, which with xtol-developed negatives usually requires only a half hour. The cyanotype was phenomenal after about 8 hours of exposure, just wonderful highlight detail. But the length of the exposure was just insanely long. I guess my problem is not so much the new versus old cyanotype or the amount of sensitizer, but just the yellow-green stain (which probably absorbs more UV than it transmits).
I use mainly calligraphy parchment and Arches watercolor paper, and I haven't found much of a difference between them (in terms of exposure) -- but the calligraphy parchment sure looks a lot sharper and dries quicker and flatter!