Well, it took a week of fine tuning all the different non-toxic acrylic-based pieces, but I finally got a good spit bite with a range of tones from light grey to deep black. The picture above shows the test strip of copper that I used to get it right. Numbers 1 to 4 were etched from 5 to 35 minutes. on a light aquatint spray of Speedball screen filler, Numbers 5 to 9 were etched for the same times on a thicker aquatint spray of Speedball screen filler. Numbers 10 to 13 were etched for the same times on an aquatint spray using the Zea Mays recipe (based on Pledge floor polish). Given that the Speedball aquatint is one that I used countless times back in the 1990s, and it smells less strong than the Zea Mays, I went with that. I etched my CULM image for 35 minutes, adding more ferric three times after minute 15. This is how the inked up plate looked:
The cloud with the word in it, and the crane, are spit bite (actually four or five applications, the last one being the darkest.) The word and the head are sugarlift-aquatint-etching. The tones in the inked up plate were so rich and dark that I said to myself, Surely it's going to work this time. Here is how it printed:
Success! Finally, the spit bite marks have that watery, ink painting feel, with a wide range of tones from grey through deep black. It has been a frustrating week, full of bad proofs and mystifying dead ends, but the wait was worth it. In a future blog post, I will write about all the materials that I used, from degreasing through to printing.
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.
In the last few years, I've been trying to do intaglio prints using the materials and techniques of so-called non-toxic printmaking. So far, the results have always been variable, at best, and mostly unsatisfactory. Just last week, I used the print facilities at an art center near my own studio to do aquatints and a hard ground etching using all the old nasty chemicals, with perfect results. But this week, I made a determined effort to try and do the same thing in the non-toxic way, and I decided to back it up by doing more detailed research and spending some cash on newer equipment. I bought a new airbrush and compressor so I could make an acrylic spray aquatint, and I mixed the spray using the recipes from the superb Zea Mays Printmaking Center's research page.
The above image shows a small 4" x 3" copper plate that already had a drypoint on it. I covered it with about a 60% to 70% dot pattern using the airbrush, and did a spit-bite etching using some old ferric and a little gum arabic. The photo shows the plate beginning to change tones as the mordant bites around the aquatint. The spit bite lasted about 20 minutes. I cleaned off the aquatint in a solution of washing soda and water. The prrof looked like this:
The watery tones are produced by the spit bite. As you can see, they could be darker, but I count this as a success, because it means that the aquatint was really strong and held up well under the mordant, and also that I could etch it even longer and almost certainly produce the deep dark tones of a spit bite etching as well.
All in all, a good day in the studio.
... but now (thanks to working on this series for nearly a year which is usually plenty of time to completely change your mind about things but luckily in this case I think I made adjustments that develop and improve the idea as well as bringing in elements that I've been playing with for several years), it looks like this:
This is my studio blog. I also have another blog, Praeterita, which contains more general art-related posts.