Wendy, the op means do you use the puffy mandrel and blow your hollows or do you just use the disk method with NO blowing into the hollow bead. Either way, two disks, side by side need to be built.
I use the puffy mandrels to make jumbo blown beads. For whatever reason, when I use the puffy mandrels, I just can't make a smallish bead. lol ! And yep, the walls of the jumbo blown beads are thin. Thin enough that the beads float and that's what you want.
Sheri, don't be afraid to use those puffy mandrels. They're alot of fun to use even when just learning to use them.