A photoluminescent retroreflective sheeting for use in structures when a power outage occurs. Guidance systems are made from this sheeting to mark exits and escape routes as well as possible hazards and safety devices. The novel sheeting includes photoluminescent properties that glow in the dark as well...http://www.google.es/patents/US5415911?utm_source=gb-gplus-sharePatente US5415911 - Photoluminescent retroreflective sheeting
