Abstract: The invention relates to a license plate for vehicles that comprises a light guide comprising a matrix of a transparent polymeric material A having distributed therein particles of a material B for scattering light within the light guide. The license plate further comprises a retroreflective sheet having a retroreflective face that faces a first side of the light guide. The invention provides for an optimized illuminated license plate, and methods of making such license plate.

Abstract: The present invention provides a semi-transparent retroreflective material having a retroreflective side (16) and an opposite rear side (17), the retroreflective material having a regular or irregular two dimensional pattern of transparent and opaque areas, said retroreflective material comprising a layer of transparent microspheres (20) and a reflective layer located functionally behind said layer of transparent microspheres, said reflective layer comprising a regular or irregular two dimensional pattern of metal areas (11) of contiguous metal and open areas (12) having substantially no metal, wherein open areas (12) of said reflective layer correspond to transparent areas of said retroreflective material and metal areas (11) of said reflective layer correspond to opaque areas of said retroreflective material and wherein said transparent microspheres (20) are present in said transparent and opaque areas and wherein said transparent areas comprise at least 5% of the total surface of said retroreflective mater