Fast-made version of my slow-drying soft ground describe in my book on page 27.
Melt 1 part soy wax (available in flakes – used for non-toxic candles ) with 1 part black Charbonnel lithographic printing ink (3-5 grams of each) in a metal cover/lid on a hot plate, stir with a wooden stick and let it get cold. Heat a copper plate on the hot plate, melt a lump of the mixture (soft ground ) on the copper plate and roll or dab it out in a thin uniform layer. Let the copper plate with the soft ground cool down to room temperature and the plate is ready to be worked in. When you are finished, etch the soft ground 30-50 min. in 12,5 Beaumé ferric chloride . The etching ground can be removed with salad oil . The soft ground will keep soft for approx. 2-3 days before it starts drying. (Soy wax is available in many hobby shops alternatively you can use soy wax from a candles).