Abstract: The assembly comprises a frame having end and side frame members, each such member including an outside wall. An inclined rear wall and a front lip extend inwardly from the outside wall. An inside wall extends rearwardly from the front lip and has a rear end constituting a ledge for a glass pane, a picture and the like. Each of at least two retaining strips associated with at least two of the frame members has a side wall carrying an inwardly directed flange and an inclined tongue. A retaining strip is applied by inserting the tongue between the rear wall and the outside wall, then pushing the retaining strip toward such outside wall until the flange rests on the backing for the picture.