For the past three weeks I've been working on the aquatints on my two plates. Aquatints are all the solid colour and tonal areas in an intaglio print. To prepare the plate for an aquatint, I have to degrease it really well. Next, I have to drop rosin onto the plate, which I do in a large rosin box, which is a wooden box with a fan at the bottom and a few tablespoons of rosin powder inside. After turning on the fan briefly, the rosin is suspended inside the box; I place my plate inside and let the dust settle for a certain amount of time (approximately five minutes). When I take the plate out again, I have an even, thin layer of dust of on the surface. The copper plate then goes on a hotplate where the rosin melts onto the surface. Wherever one of the rosin-dust grains melts to the plate, it will resist the acid. The acid, therefore, will bite between all the microscopically small dust grains creating a fine dot pattern or small pits that will later hold the ink. This is where the stage-biting starts, meaning I etch the plate in intervals while stopping out parts that are etched long enough. Once the plate has the rosin on the surface, for example, I stop out (paint with asphaltum) all the areas I want to remain white or don't want to hold any tone (see image above). Then I etch the plate for the first stage at 15 seconds for a really light grey, take it out of the acid, rinse it off, stop out all the areas I want to keep at the lightest grey.
Then I etch the next stage, doubling the time for my next tone and I repeat this process until I have etched about seven stages, which will give me a nice range of tones from very light to medium tone to a rich black or a deep colour (so, I etch 15 sec, 30sec, 1min., 2min., 4min., 8min., 16min.). Below is a detail after the 1 minute etch. I do this whole process on both plates, etching different areas on each plate which will hopefully work well together once they overlap.
Working on two plates makes it a bit tricky to think about where the colours will go and where colours will overlap with greys to create different tones. I've made a colour map by painting water colours onto my line-etch. While it's pretty ugly at this stage and the colours aren't quite true to the etching inks, this map does help me to visualize the colours and tones as I work my way through the different stage-bites. I'm planning on wiping two colours à la poupée on the key plate and two or three colours on my second plate, possibly adding a stencil roll as well, that's why you see so many colours in my sketch. This might change later as I edit the plate. I'm also planning on doing some soap ground or spit bite in the blank area in the center.