- Glass jar
- Wallpaper paste (the powdered stuff)
- Plastic teaspoon
- Plastic toothbrush
- Caustic soda (sometimes sold as oven cleaner)
- Mask, rubber gloves, goggles -- caustic soda is dangerous.
- Well-ventilated room or outside space
- Fill the jar one third full of water.
- Add one teaspoon of wallpaper paste to the water. Stir, and then leave for five minutes.
- Put on mask, gloves, and goggles.
- Add two teaspoons of caustic soda to the paste. Stir. After a few moments, you can feel the glass jar warming.
- Use teaspoon to apply caustic soda to the lino.
- Leave for twenty minutes to two hours.
- Wash the lino in running water. Wash it again. And again. The toothbrush helps to clean it.
- Remove mask, gloves, and googles.
These examples show the effect of different etching times. We used two types of lino: "Grey" is T N Lawrence 3.2mm, and "Brown" is Great Art's; cut lots of blocks, each about 8 x 6 cm; put on the caustic soda; and removed, cleaned, and printed a block at intervals.
10 minutes, Grey lino: Already something happening here.
10 minutes, brown lino: Nothing happening here (I think the white dots are the result of bad inking).
30 minutes, Grey: Now something's happening! The lighter parts are where the caustic soda has started to etch the lino. Though we put the soda on randomly, it's easy to find images emerging in the print.
40 minutes, Grey:
50 minutes, Brown: At last the brown lino is starting to show the effect.
60 minutes, Brown.
60 minutes, Grey
That's all the tests for today. As you can see, the grey lino etches much faster than the brown. Next, we'll try etching the brown lino for longer, to see how far it can be pushed. Does it disappear completely if you leave it long enough?