So, I printed that first plate. It was a bit blotchy. A total of 38 minutes was too much, but it was clear that the 5 minutes and thereabout etches got a nice shade of grey. I hadn’t been very systematic but it was a ball park figure. The stop-out pens worked well, gave clean lines. The airbrush sprayed on stop-out gave a lovely soft effect. The wax crayon was textured slightly. The litho pencil was a bit faint. So…
Made a plan for a test plate, wrote it down, had breakfast to think it over, trying not to make a stupid mistake.
Opened a new copper plate, and filed the edges. Took the Mylar off one side and spent ages trying to get it off the other side before deciding there wasn’t any. De-greased it in soya sauce. Sprayed it with airbrushed aquatint, but didn’t get a uniform layer. This bit is hard. Left it to dry.
Cut a backing sheet of sticky backed plastic, and 17 strips of one cm each. Planned to remove one strip each minute, so getting from 0- 18 minutes in intervals of one minute.
I started, and was surprised at how deeply bitten the plate was even after one minute, so decided to half the intervals. So ended up with 0- 9. 5 minutes.
Printed it, and observed that the short times at the start were quite distinct- 30 seconds was quite different to one minute, and the stages up to about 3 minutes were clear to see. After that there was no clear boundary, and the colour just got gradually darker, though not absolutely black. Two or three possible reasons for that:
1. My ink was very thick- I added some aqua wash oil and it got blacker.
2. The aquatint layer wasn’t uniform- where it was thicker, the black was more dense.
3. Perhaps the immersion was too short this time, but I feel it shouldn’t be much longer.
Anyway, established that the intervals are more critical at the early stages.
Inked it again with Charbonnel inks and wash oil to see if the blacks would get more black. They did. It was looking like my ferric was strong, as I was getting blacks quite fast. The baumeter seemed to be telling me nothing.
Made the following list of key times:
Also noted I should file the plate away from the front, as there was a decidedly hard edge.
Should have changed my intervals after about 6 minutes.
Should have stopped and had a coffee and thought it through….