I found my package of "Perfect Circles" - circle templates designed by Karen Kay Buckley
and they do make perfect circles. I also found some silk organza I had dyed and the color was perfect. It is transparent so the background showed through. Using an opaque fabric would add another strong design element to the surface and it was busy enough.
I backed the organza with fusible web and started cutting circles.
The letter J - upside down in block below is an old block from type set letters I picked up at a stamp show.