Found something interesting last night (on an Antique Roadshow episode). Someone was having appraised some drypoint works. Never heard of this before. They were beautiful. Wiki describes it as "Drypoint is a printmaking technique of the intaglio family, in which an image is incised into a plate (or "matrix") with a hard-pointed "needle" of sharp metal or diamond point. Traditionally the plate was copper, but now acetate, zinc, or plexiglas are also commonly used".
Angie, isn't this essentially, or at least similar, to what you've been doing?