I wasn't really into yo-yos before this. On good days, I can barely make a yo-yo sleep.

I have friend who is, though, and when I asked about various designs, he would just go off about various types. :) He was the one who taught me about the various shapes of yo-yos and how they influence how easily they can sleep or come back. I was then able to relay this information back to my group, and we decided on the design from there.