Abstract: Improved illumination of edge illuminated signs is achieved by use of light guides of transparent material to match the aperture of an edge of a sign panel to the aperture of a light source which may be located remotely. The light guide is typically of ribbon section at the panel end and of compact section at the other. It may be formed by dividing a continuation of one edge of the panel into individual fibres. The compact end of the guide may be fitted with a ferrule for coupling to further light guide elements. The sign panel is preferably covered with internally reflective or phosphorescent material except in the regions of indicia formed on the surface of the panel by masking, abrasion or hot stamping.