This is another post where I talk about my own research into how to obtain the best results from non-toxic etching materials -- specifically, the Baldwin Intaglio Ground. This is a form of etching resist developed by printmaker Andrew Baldwin, from the UK, as a non-toxic alternative to the nasty chemicals contained in traditional hard ground and soft ground resists. It comes in a tube, and when you squeeze some out onto an inking slab it looks like etching ink. You roll it onto the copper plate with a brayer, as if you were inking a relief block, in contrast to the traditional hard grounds, which are either melted onto the plate or poured on as a liquid hard ground. Applying the BIG to make a hard ground is relatively easy. Using it as a soft ground can be quite tricky, and it has taken me many tries and many failures to achieve a satisfactory etch.
The main problem, unfortunately, is the lack of specific instructions in preparing the BIG soft ground. Andrew Baldwin has some excellent training videos on his website, but they do omit some quite crucial bits of information at key points. The Zea Mays studio in the US has many pages of research information about drawing into a BIG soft ground, though they don't have anything about pressing textured materials into the ground to leave an impression that can be etched. The best description of this process that I've found is here, on the blog of printmaker Kristen. But here is my attempt to describe precisely what I discovered:
1. Clean your brayer and inking slab with isopropyl alcohol and rags to ensure that they are both completely clean and degreased.
2. Squeeze out a line of BIG to the width of your brayer, then flatten it into a wider band using a palette knife. If you can, it's a good idea to use a brayer as wide as the copper plate.
3. Roll the brayer into the BIG until there is just enough to cover the brayer. Key point: don't make it a thick coverage of BIG on the brayer.
4. Roll the BIG onto a degreased copper plate until most of the sparkle of the copper has gone. Key point: there should be a thin layer of BIG on the plate, not sticky and thick. Roll in different directions until the plate is mostly covered. If you need to go back to the slab to get more BIG, again make sure that you are only rolling the brayer up with just enough, not too much. 90% coverage at this stage is fine (that is, it's ok if a few dots of copper show through the thin layer of BIG).
5. Set up the press as follows: remove the sizer blanket, use just the cushion and the pusher; tape a piece of 230 mesh screenprinting fabric to the bed of the press, large enough to cover your copper plate; set the press pressure exactly the same as you normally use for printing your plates.
Key point: no substitutions for the mesh. I tried other types of material, and nothing worked until I used precisely this kind of screenprinting fabric.
6. Place the rolled up plate on the bed of the press, carefully place the mesh over the plate, then a piece of newsprint over both.
7. Lower the blankets and roll the plate-mesh-newsprint.
8. Carefully lift the mesh back from the plate. There should be a dark rectangle on the mesh from where it has picked up some of the ground. This is a good thing, as this helps to reduce the amount of foul biting on the plate that often happens with soft ground etching.
9. Take the copper plate back to the inking slab. Roll another thin layer of BIG onto the plate. Key point: keep it thin! I have found that it takes just two or three rolls of the brayer on the plate to complete this step.
10 .Now take the copper plate back to the press, and place it in the same spot as in step 6. Arrange your materials (leaves, thin fabric, feather, string, etc) carefully on the plate. This is a one-drop step: don't pick them up and move them around, as this will mess up the resist.
11. Place the mesh carefully back over the plate, and cover everything with newsprint.
12. Roll the press.
13. Carefully lift back the blankets, the newsprint, and the mesh. Use tweezers or a fine point etching needle to remove the leaves, feathers, etc. The impression in the soft ground should look something like this:
Note that with the large leaf, you can see a lot of exposed copper in the stem, and less in the veins. This is a good thing. The different amounts of resist that are lifted away by your materials will etch in a pleasant variety of contrasting tones. Things that can go wrong at this stage: not enough resist has been removed, so nothing will etch; too much resist has been removed, and the image will etch as foul bite.
14. Cure the plate as follows: convection oven, 6 minutes at 275 f with the convection fan going/hot plate: 210 f for 35 minutes.
Whichever heat-set method you use, let the plate cool off and cure for 30 minutes before etching the plate.
15. If you can, it's a good idea to stop out the non-etching areas using a brush and black acrylic paint. Let the paint dry before you etch the plate.
16. Etching time: in a tank of 38 baume ferric chloride, I found that a plate that looks like the ones in the above photo needed between 40 and 55 minutes to achieve a wide variety of tones. You should still take the plate out of the ferric every 15 minutes to check that the resist isn't breaking down too quickly.
Another tip: if you want to rinse the plate in order to check the progress of the etch, do so very carefully. If you run the tap too forcefully, the water might wash away some of the resist. What I do: turn the tap on so that there is a tiny stream of water, then let it run down from the top of the plate, preferably starting on a non-etching area.
If some areas seem to be etching more quickly than others, carefully rinse the plate, dry it, and stop out those areas before continuing the etch.
Here is a print I took from a plate that was prepared according to the above instructions, with leaves and string pressed into the soft ground, then etched for 55 minutes:
Remove BIG from the plate, the brayer, and the inking slab using De-Solv It (a citrus based nontoxic solvent).
The main problem, unfortunately, is the lack of specific instructions in preparing the BIG soft ground. Andrew Baldwin has some excellent training videos on his website, but they do omit some quite crucial bits of information at key points. The Zea Mays studio in the US has many pages of research information about drawing into a BIG soft ground, though they don't have anything about pressing textured materials into the ground to leave an impression that can be etched. The best description of this process that I've found is here, on the blog of printmaker Kristen. But here is my attempt to describe precisely what I discovered:
1. Clean your brayer and inking slab with isopropyl alcohol and rags to ensure that they are both completely clean and degreased.
2. Squeeze out a line of BIG to the width of your brayer, then flatten it into a wider band using a palette knife. If you can, it's a good idea to use a brayer as wide as the copper plate.
3. Roll the brayer into the BIG until there is just enough to cover the brayer. Key point: don't make it a thick coverage of BIG on the brayer.
4. Roll the BIG onto a degreased copper plate until most of the sparkle of the copper has gone. Key point: there should be a thin layer of BIG on the plate, not sticky and thick. Roll in different directions until the plate is mostly covered. If you need to go back to the slab to get more BIG, again make sure that you are only rolling the brayer up with just enough, not too much. 90% coverage at this stage is fine (that is, it's ok if a few dots of copper show through the thin layer of BIG).
5. Set up the press as follows: remove the sizer blanket, use just the cushion and the pusher; tape a piece of 230 mesh screenprinting fabric to the bed of the press, large enough to cover your copper plate; set the press pressure exactly the same as you normally use for printing your plates.
Key point: no substitutions for the mesh. I tried other types of material, and nothing worked until I used precisely this kind of screenprinting fabric.
6. Place the rolled up plate on the bed of the press, carefully place the mesh over the plate, then a piece of newsprint over both.
7. Lower the blankets and roll the plate-mesh-newsprint.
8. Carefully lift the mesh back from the plate. There should be a dark rectangle on the mesh from where it has picked up some of the ground. This is a good thing, as this helps to reduce the amount of foul biting on the plate that often happens with soft ground etching.
9. Take the copper plate back to the inking slab. Roll another thin layer of BIG onto the plate. Key point: keep it thin! I have found that it takes just two or three rolls of the brayer on the plate to complete this step.
10 .Now take the copper plate back to the press, and place it in the same spot as in step 6. Arrange your materials (leaves, thin fabric, feather, string, etc) carefully on the plate. This is a one-drop step: don't pick them up and move them around, as this will mess up the resist.
11. Place the mesh carefully back over the plate, and cover everything with newsprint.
12. Roll the press.
13. Carefully lift back the blankets, the newsprint, and the mesh. Use tweezers or a fine point etching needle to remove the leaves, feathers, etc. The impression in the soft ground should look something like this:
Note that with the large leaf, you can see a lot of exposed copper in the stem, and less in the veins. This is a good thing. The different amounts of resist that are lifted away by your materials will etch in a pleasant variety of contrasting tones. Things that can go wrong at this stage: not enough resist has been removed, so nothing will etch; too much resist has been removed, and the image will etch as foul bite.
14. Cure the plate as follows: convection oven, 6 minutes at 275 f with the convection fan going/hot plate: 210 f for 35 minutes.
Whichever heat-set method you use, let the plate cool off and cure for 30 minutes before etching the plate.
15. If you can, it's a good idea to stop out the non-etching areas using a brush and black acrylic paint. Let the paint dry before you etch the plate.
16. Etching time: in a tank of 38 baume ferric chloride, I found that a plate that looks like the ones in the above photo needed between 40 and 55 minutes to achieve a wide variety of tones. You should still take the plate out of the ferric every 15 minutes to check that the resist isn't breaking down too quickly.
Another tip: if you want to rinse the plate in order to check the progress of the etch, do so very carefully. If you run the tap too forcefully, the water might wash away some of the resist. What I do: turn the tap on so that there is a tiny stream of water, then let it run down from the top of the plate, preferably starting on a non-etching area.
If some areas seem to be etching more quickly than others, carefully rinse the plate, dry it, and stop out those areas before continuing the etch.
Here is a print I took from a plate that was prepared according to the above instructions, with leaves and string pressed into the soft ground, then etched for 55 minutes:
