A retroreflector has an arrangement of triples, each having three side surfaces that stand essentially perpendicular on one another. The triples are disposed on a curved or domed surface. The geometry of the triple array is adapted to the curved surface, to even out the thresholds, and extend the side surfaces of a triple. The extensions of the side surfaces project into adjacent triples. Due to the extension projecting into adjacent triples, joints are formed there, which even out the uneven area. The joints can assume the form of a protrusion filled with material or a notch in which material is missing. A forming die produces the retroreflector and a method produces the forming die. The retroreflectors have geometries having full cube surfaces, in other words Full Cubes, for curved or domed surfaces or free-form surfaces.