A sign is edge lit and illuminated by an array of light emitting diodes disposed along an edge of a light transmissive panel. A light diffusion surface, which can be formed by a series of serrations on the panel edge, disperses light from the discrete light emitting diodes in the array. A geometric figure, which can be text or graphics or both is formed on one face of the panel by grooves, which redirect diffused light so that an illuminated image, corresponding to the geometric figure, can be seen on the front of the panel. The grooves forming the figure and the light diffusion surface comprise parts of a one-piece panel, and the grooves and the light diffusion surface can be formed when the panel is injection molded.