I was rummaging around the front bedroom where I’m doing my college work and found a sketchbook that I did when was on my foundation art course.
These are etchings, created on metal plates by painting areas with a varnish and then putting the plates in an acid bath to etch away the surface. Then to get more detail you can cover more of the plate with varnish or a wax resist. Acid bath again, rinsing it off before adding more wax or varnish. You can also use something called aquatint which gives you an interesting background. I’m remembering this from over 40 years ago. So I might not have it right. Eventually you ink up the plates and place them onto paper which you then put in a press and squash them together. These are the result.