and the main safety ingredient in all our product line. Adding Retro-reflectivity to road marking paints is a major factor in increasing road safety in a very cost-effective way. Our glass beads exceed all federal & international standards for roundness, granularity and retro-reflectivity. Made from the purist Egyptian silica, our glass beads reach a refractive index RI ≥1.9 which is the standard for airplane runways!