Design Decisions

Yesterday I had a wonderful time in my wet studio playing with plain and coloured discharge paste. I'm preparing more samples for my workshops at Quilters Dream in Edmonton next month. I made some fat quarter sized circles on black:

I then layered them on top of one another, cut them into quarters and schuffled the quarters around.

I pulled out every thread I could find that would work on the discharged circles and quilted one of them heavily all over:

The other one awaits the sandwiching and quilting. Now, here's my dilemma---I like the uneven outer edges, maybe trimmed down a little bit. I'm thinking of leaving the edges like that, perhaps putting the piece on a deeper red or purple backing, perhaps quite narrow. What do you think?

I like this technique and could see doing lots more of these, perhaps larger and smaller blocks in a "sort of" mosaic. Options?