A plastic drywall accessory includes an elongated strip of plastic having a nose and at least one wing projecting outwardly from a stepped edge of the nose. A hinge of flexible plastic is interposed between the nose and wing, so the wing will closely conform to an associated wall surface. In a first embodiment, the accessory is co-extruded, with the wing and nose formed of a rigid plastic material and the hinge formed of a flexible plastic material. In a second embodiment, the accessory is co-extruded, with the nose formed of a rigid plastic material and the hinge and wing formed of a flexible plastic material.