But I digress.
I scanned a dried but not exposed sheet of Arches Platine to illustrate the color to expect of a good emulsion and as I retrieved the paper to print my digital negative to show the next step I noticed it had partially printed out where it was exposed to the scanner fluorescent light.
Did I mention the cyanotype process is a printing out process?
The cyanotype process is slow as these things go, exposure that is. Depending on the strength of your UV light source exposures can range to 15 minutes or more. I was somewhat surprised that the sheet partially printed out from the scanner light, but shouldn't have been.
For the UV sensitive alternative processes you don't work in a darkroom as much as a dim room. I use a low wattage incandescent bulb, definitely not one of the newer energy efficient fluorescent replacements! If I coat multiple sheets of paper, I will put them in a black portfolio box to keep away from all light. If I'm simply drying a couple sheets for some quick work I leave out and I don't stick around to watch - but do turn off the incandescent light while I go watch another episode of Tales of Tomorrow.
For reproducible results, and preservation of one's sanity, controlling variables such as ambient illumination, humidity, and temperature can eliminate transient problems in your work.
That said, I am quite vexed by a mottling of the lighter mid-tones of my test cyanotype image. Another test awaits.