Retroreflective sheetings have the ability to redirect incident light towards its originating source.  This ability has led to the wide-spread use of retroreflective sheetings on a variety of articles.  There are essentially two types of retroreflective sheeting: beaded sheeting and cube-corner sheeting.  Beaded sheeting employs a multitude of glass or ceramic microspheres to retroreflect incident light.  Cube-corner sheeting, on the other hand, typically employs a multitude of rigid, interconnected, cube-corner elements to retroreflect incident light. 
Flexible retroreflective sheeting, particularly well-suited for use on irregular surfaces or for attachment to flexible substrates such as a road worker's safety vest has been described.  See for example, U.S. Pat.  Nos.  5,450,235; 5,691,846; 5,784,197 and 6,318,867.