A frame apparatus for displaying a flat article and a combined frame apparatus and flat article. In one aspect, the frame apparatus comprises an annular display frame, a transparent front panel, a rear panel, and an annular spacer frame. The annular display frame comprises a rabbet defined by a floor and a wall, the wall comprising a first engagement portion and a second engagement portion. The annular spacer frame is coupled to the first and second engagement portions of the annular display frame by interaction between a first and second locking member of the annular spacer frame and the first and second engagement portions of the annular display frame. The first and second locking members extend into the first and second engagement portions and apply a compression force to retain a flat article between the transparent front panel and the rear panel.