Method for forming retroreflective sheeting

A method for forming a mold for making retroreflective sheeting comprising the steps of:

• a. forming a plurality of bundles of pins by clamping pins together along their longitudinal axes, said pins each having a top surface, such combined top surfaces in a bundle of pins providing a substantially planar surface for said bundle of pins;
• b. inscribing on the planar surface of each bundle of pins a continuous pattern of cube-corner trigonal pyramids;
• c. releasing each bundle of pins for allowing removal and rotation of the pins;
• d. interchanging the pins between the bundles forming a plurality of new bundles of pins having disoriented patterns of cube-corner trigonal pyramids;
• e. forming a mold for making retroreflective sheeting from the disoriented pattern of cube-corner trigonal pyramids on at least one of the new bundles of pins.

A method for forming retroreflective sheeting having a plurality of retroreflective cube-corner trigonal prisms distributed over one of its surfaces, the prisms disposed in a planar array having a plurality of zones of prisms having differing angular orientation, comprising the steps of:

• a. forming at least one bundle of pins by clamping pins together along their longitudinal axes, said pins each having a top surface, such top surfaces combining to form a substantially planar surface on the bundle of pins;
• b. inscribing on said planar surface a continuous pattern of cube-corner trigonal pyramids;
• c. releasing the bundle of pins for allowing removal and rotation of the pins;
• d. rotating the pins within the bundle about their longitudinal axes for providing differing angular orientation of the pyramid pattern;
• e. rebundling the pins by reclamping the rotated pins together;
• f. forming at least one mold from the disoriented pattern of cube-corner trigonal pyramids on the bundle of pins;
• g. forming from said mold retroreflective sheeting having a plurality of retroreflective cube-corner trigonal prisms disposed in a planar array having a plurality of zones of prisms having differing angular orientations.