Porcelain · Form
A rim folded outward into a distinct flange, giving the hand a cooler, defined gripping edge.

The Form
A flanged rim turns outward from the body in a distinct, folded edge. On a gaiwan the flange serves the hand: when the water is kept below it, the edge stays comfortable to hold while pouring.
Not to be confused with a folded waist (折腰), where the angle sits in the body of the vessel rather than at the rim.