A retroreflective article includes a flat front surface, and a structured rear
surface displaced from the flat front surface. The structured rear surface is provided
with arrays of sets of three mutually perpendicular lateral triangular sides, and
a plurality of trigonal linear prisms. The three lateral triangular sides have
a common apex and uncommon linear base edges. The linear prisms are disposed along
at least one of the linear base edges of the three lateral triangular sides.
