Continuing with the spit bite process, I used a small old copper plate to do a timed test. Once again, I tried to follow the instructions from the brilliant Zea Mays research website as closely as possible. So:
* I mixed their recipe for acrylic aquatint spray (Pledge floor polish, waterproof ink, GAC 100, flow release, airbrush medium...)
* I used the airbrush to apply the spray to about 50% to 60% coverage.
* I applied the spit bite in six different ways to the plate.
Looking at the print in the above photo, starting at the top and moving right to left, they are:
2 minutes then blotted dry.
10 minutes then blotted dry.
20 minutes, more ferric added at 12 minutes.
8 minutes, adding water at 5 minutes.
Etched for 15 minutes, adding water and more ferric at 12 minutes.
Lastly, the bottom areas were etched for 30 minutes, adding more ferric at 10 m and 20 m.
The result therefore seems to be that if you get the aquatint right, you can make a solid grey tone after 5 minutes, you can get dispersed grey tones by adding water during the etch, and the darkest tones of all occur between 25 to 30 minutes. I will next apply these findings to the CULM image I started last week.
This is my studio blog. I also have another blog, Praeterita, which contains more general art-related posts.