I have learned something.... I normally use Miyuki seed beads, never Toho, because Toho are a tiny bit fatter and larger than Miyukis. I tried making the base with Miyukis, and by the time I got to put the rivoli in and pull tight the 4mm bicones, the rivoli kept falling out and the crystals weren't framing right. So I scrapped and started over with a tube of Toho's I happened to have on hand. TOTALLY DIFFERENT RESULTS! I was able to cinch up the crystals around the rivoli perfectly, keeping it locked in. So, with this pattern, it's essential to use Toho's in the base with the superduos or else you're not going to be able to frame the rivoli.