I made a cyanotype at the Lower East Side Printshop today. We mixed cyanotype solution part A with part B using a graduated cylinder, careful to fill the cylinder to the 50 mL mark. The curve of the liquid in a cylinder is called the meniscus, Romona and I remembered together.
After mixing the chemical we applied it to paper using spongy brushes and covered it with plastic trash bags to prevent UV exposure. Once the paper dried we put it behind plastic films (not mylar, but another similar material) and hermetically sealed the glass plated emulsion tank. We exposed the screen using a UV bulb and measurement unit.
We began at 600 lumens, and then taped rubylith to block the UV light from entering one of the test strips, creating consecutive exposure tests for 600, 700, and 800 lumens. The rubylith functions in a similar way to a piece of cardboard covering photo-sensitive paper does while making a test strip in a photography darkroom.
After removing the cyanotype and washing the exposed paper in a flat tub, we discovered the exposure was not strong enough to show the lighter tones on the test strip. We then repeated the experiment using a longer exposure time, setting the machine for 900 and adding incriminates of 100, giving us readings at 10, 11, and 12.
The tests still were not giving enough detail in the lighter ranges, and we determined that the paper needed to be soaked properly in a tub, rather than painted on one side using long film strokes with a spongy brush. I soaked the paper in a plastic bin, shifting the lips on the sides so that the chemical reached the paper’s edges evenly. We set the paper to dry and I added a scrap to the chemical bin.
The paper dried while we touched up films from a woman named Lori Hunt (she sent large patterns of ‘wallpaper’ which reminded me of calming optical illusion books, but printed them with matte black ink, which does not hold well on the plastic film) We checked the films for fingerprints and pinholes, and I drew a quick sketch on scrap film using the oil-based sharpies. A face, loose, dark on one half.
When the paper was dry and we had finished covering Lori’s films, we returned to finish the cyanotype tests. I was planning to do my experiment after the others, but Marco asked if I wanted to add it to the test.
“Sure, I’ll do mine now.”
I stuck down the sharpie drawing, grabbed a wobbly wood frame, and put my scrap paper between the drawing and the frame, then vacuumed shut the machine.
We exposed three half tone and greyscale test strips at 16, 18, and 20. I set the machine for 800 lumens and ran it twice, covered 2 tests with rubylith, and ran the bulb for 200. My sketch stayed exposed the whole time. I repeated the same process with another strip covered, and removed the cyanotype tests from the large exposure unit, and put them in a large bin filled with water to wash. I removed my experiment and put it on the drying rack to look at tomorrow.
The final image reads 6 tone tests exposed on cyanotype: 3 half tone tests and 3 accompanying greyscale tests, exposed at intervals of 200 lumens. The greyscale images printed more clearly than the halftones. The proper exposure for our unit is somewhere between 16 and 20, but there are still discrepancies in the paper, and the exact exposure will depend on an even application of chemical to paper or cloth.