A drywall finishing system for finishing normal inside and outside corners of any angle. The finishing system comprises a preformed trim piece comprising a semi-rigid member that is relatively thick in the center and tapers laterally to a thin edge or is stepped forming a thick and thin portion. A layer of fibrous can be bonded to the inside surface of the semi-rigid member for receiving joint compound to continuously bond the trim piece to the dry wall. A layer of finishing material can be bonded to the exterior surface of the semi-rigid member. The finishing system can be attached to a wall with fasteners such as nails.