Abstract: A corner bracket comprises a corner piece and an integrally attached pin. In one embodiment, the corner piece is a single, integrally-formed molded plastic piece having front and rear walls joined by sidewalls. The pin may be made from metal and be molded into the juncture between the sidewalls. The molded-in end of the pin extends inwardly nearly to the front face of the corner piece. The pin may also be molded plastic integrally molded with the corner piece. In either case, the pin projects from the rear face and terminates in a pointed end for attachment to a vertical surface. The corner piece defines a slot dimensioned to receive a corner portion of an object to be mounted, such as a mat frame. In another embodiment, the front and rear walls of the corner piece are attached to each other by a hinge. The walls and the hinge are preferably integrally molded from plastic. Edge portions of the front and rear walls are provided with snap-together interlocking portions.