After basic line etching, but before learning aquatint, I tried another line drawing technique that used soft instead of hard ground. While hard grounds are fairly impervious and are removed with the point of needle for creating clean lines, soft grounds respond to more subtle touches. Touching a soft ground will expose the grooves of a fingertip, allowing acid to bite a fingerprint on the surface. This means more care must be taken when handling the plate, but it also allows for more natural looking drawings, with thin and thick edges of a pencil:
I wasn't particularly excited about my soft ground self portrait as it lacked punch. So when we learned a salt etching technique, I reused the plate:
Melting salt on the plate removes hard ground in a grainy pattern. The salt can be arranged on the plate to create the desired image, but I chose to use the salt as if it were resin for an aquatint. It created a looser, grainier dot matrix, that I exposed in several stages with lighter areas progressively protected, much like an aquatint.
I actually laid a second salt ground to get even darker areas and more contrast. I then tried printing with a transparent color rolled over the plate.