RETROREFLECTIVE ARTICLES HAVING MOIRÉ-LIKE PATTERN

摘要

The invention relates to retroreflective articles comprising a sheeting having a microstructured surface that reflects light in a moiré-like pattern. The invention further relates to methods of making a master and replicas thereof including tooling that results in sheeting having such pattern. A preferred method comprises forming V-shaped grooves in a substrate (e.g. metal plate) wherein the intersections of three grooves form cube-corner elements. The cube-corner elements are formed in such a manner that adjacent parallel grooves have substantially the same groove spacing and groove depth throughout the array. The master as well as corresponding tooling and sheeting preferably have a groove spacing within the range of about 0.0005 inches (0.0127 mm) to about 0.007 inches (0.1778 mm) throughout the array and more preferably a groove spacing of less than about 0.004 inches (0.1016 mm).