Retroreflective traffic sign and process and apparatus for manufacturing same

A method， apparatus for making， and a retroreflective traffic sign consists of a polymeric film having a front face and a rear face， wherein the rear face has a pattern of microprismatic retroreflective elements integrally formed as part of said film; a pattern of cell walls formed of an adhesive-containing polymer defining cells in which the microprismatic retroreflective elements are in the cells; and a substrate is adhered directly to the cell walls formed of the adhesive-containing polymer while leaving an air gap between the microprismatic retroreflective elements and the substrate in the cells.