Abstract: A sign is formed from a plurality of panels abutted edge-to-edge. A main elongate reinforcing member has a transverse head for attachment thereto of a mounting device for the sign, and a depending leg terminating in an offset foot secured to the rear of a first sign panel adjacent an abutting edge of the panel. A second, elongate, reinforcing member has a generally L-shaped cross-section including a foot portion secured to the rear of an adjacent second sign panel at the edge abutting the first panel and an upright portion abutting the leg of the main reinforcing member. One of the reinforcing members has a flange at the foot projecting into a recess in the foot portion of the other reinforcing member. The head of the reinforcing member is offset with respect to the leg on the opposite side from the projection of the foot to expose the foot for rivetting to the plate.