Abstract: The bracket system comprises specially shaped corner components which include an angled slot for receiving the corner of the poster to be mounted. A locking mechanism comprising a pair of members which rotate relative to one another are inserted in the slot behind the poster corner. The locking members include ramped surfaces which engage one another to expand them outwardly and grip the poster corner in the slot. Thus, the poster is firmly gripped in the corner component. A tack like protrusion carried on the back side of the corner component is used to fasten the resulting assembly to a wall surface in a conventional manner, while leaving the poster undamaged.