A frame for a sign. The frame comprises a plurality of struts and corner brackets. The struts have an exposed front surface including a gripping means. Each corner bracket slidably engages with two of the struts at an angle. The corner brackets also have an exposed front surface including a gripping means. The gripping means of the struts is substantially continuous with the gripping means of the corner brackets so that when the corner brackets and struts are engaged to form a polygon, the polygon includes a substantially continuous gripping means that is engageable with a sign to mount the sign on the frame.