Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Page 7 Page 8 Page 9 Page 10Glass Bead Technology Retroreflective materials are so commonplace on jobsites across the country that most people don’t think about them beyond knowing they are a safety technology that enhances visibility. What exactly is retroreflectivity, and how does it work? A reflective surface does not absorb light, but projects it away. In Latin, “retro” means “backward.” A retroreflector is a surface that reflects light back to its original source with minimal scattering. Retroreflective materials have been used for decades in road safety application, alerting drivers to dangers and the people working on or near roadways. Today there are two major categories of retroreflective materials: beads and prisms. The material that pioneered retroreflection for road safety was glass beads. According to Shari Franklin Smith, a technical service manager at 3M®, a leading manufacturer of retroreflective materials, glass beads were first used in the 1930s. During this period, road safety became a priority as the number of vehicles on the road increased. The beads were mixed with paint to illuminate pavement markings at night. GLASS BEADS BINDER LAYER BACKING REFLECTOR COATING Retroreflection Did you know? The inspiration for using glass beads came from seeing the concentrated light reflection in a cat’s eye in darkness. THE history of two retrore The spherical shape of a glass bead is capable of capturing light from 360° and reflects it back to the source. This capability of reflecting light from multiple angles works well when used for materials that are not perfectly flat, such as high-visibility clothing or road paint.