I next decided to design an art card (2.5" x 3.5") with a similar theme:
Couple months later, she contacted me again and asked if I was willing to design another piece for her on the same theme, but double layered. It sounded like a fun idea, so I did so. Similarly, the second cutting from that pattern sold shortly after.
So I designed Neurons III- another layered piece. And sold both editions of that one in fairly quick succession this past summer.
Neurons IV (layered again) is currently in my sketchbook under development. I am hoping to have the patterns finished to my satisfaction within the next couple months.