A patient interface device and cushion for the device are respectively disclosed, for preferred CPAP and BiPAP breathing masks. The cushion has a composite structure with an open rounded polygonal profile defining a mask side layer and a slip-resistant fibrous patient side layer, with an intermediate barrier layer positioned between the first and second layers. The layers are integrally bonded together into a three-dimensional conformation defining a J-shaped cross section and an inboard patient side curl opening into an air chamber juxtaposed with one or more of the patient's airways. The body exhibits flexibility between about 4 and about 10 Taber Stiffness Units. Method and apparatus for making the cushion are further described.