Patterned sheet material

Claim 1

SYNTHETIC PLASTIC MATERIAL FOR PRODUCING A VISUAL MOIRE PATTERN HAVING A BODY PORTION OF SUBSTANTIAL LENGTH AND WIDTH DIMENSIONS PROVIDING FRONT AND REAR SURFACES, SAID MATERIAL BEING OF SUBSTANTIALLY UNIFORM THICKNESS AND HAVING A MULTIPLICITY OF CLOSELY SPACED CURVILINEAR LENS-LIKE EMBOSSMENTS ARRANGED IN A FIRST PATTERN ON THE FRONT SURFACE THEREOF, EACH LENS-LIKE EMBOSSMENT PROJECTING ON AN AXIS PERPENDICULAR TO SAID FRONT AND REAR SURFACES, SAID MATERIAL ALSO HAVING A MULTIPLICITY OF CLOSELY SPACED REFLECTIVE EMBOSSMENTS ARRANGED IN A SECOND PATTERN ON SAID REAR SURFACE, EACH REFLECTIVE EMBOSSMENT PROJECTING ON AN AXIS PERPENDICULAR TO SAID FRONT AND REAR SURFACES, EACH OF SAID LENS-LIKE AND REFLECTIVE EMBOSSMENTS DIMINISHING IN CROSS-SECTION OUTWARDLY FROM SAID BODY PORTION IN ALL PLANES WHICH INCLUDE ITS PERPENDICULAR AXIS TO PROVIDE SIDE WALLS TAPERING INWARDLY FROM SAID BODY PORTION TOWARD SAID PERPENDICULAR AXIS, EACH OF SAID LENS-LIKE EMBOSSMENTS BEING CURVILINEAR IN CROSS SECTION IN ALL PLANES WHICH INCLUDE SAID PERPENDICULAR AXIS AND IN ALL PLACES WHICH EXTENDS NORMALLY THROUGH SAID PERPENDICULAR AXIS, SAID REFLECTIVE EMBOSSMENTS PHASING IN AND OUT OF PERPENDICULAR AXIS REGISTRY WITH SAID LENS-LIKE EMBOSSMENTS IN AT LEAST ONE DIRECTION OF SAID SURFACES TO PROVIDE VARYING OPTICAL EFFECTS DUE TO VARIATION IN THE ANGLE OF INCIDENCE OF LIGHT RAYS FOCUSED BY SAID LENS-LIKE EMBOSSMENTS OF SAID FRONT SURFACE ONTO THE TAPERING SIDE WALLS OF THE REFLECTIVE EMBOSSMENTS OF SAID REAR SURFACE, THE CENTER-TO-CENTER CLOSE SPACING OF SAID LENS-LIKE EMBOSSMENTS DEVIATING NOT MORE THAN 10 PERCENT FROM THE CENTER-TO-CENTER CLOSE SPACING OF SAID REFLECTIVE EMBOSSMENTS, SAID CLOSE SPACING OF SAID LENS-LIKE AND REFLECTIVE EMBOSSMENTS PRECLUDING ANY BANDS OF FLAT SURFACE THERE-