This article discusses the manufacture and use of glass beads. Just over 100 years ago, technicians were working on an experiment when they found a glass bead in the residual ash. This was not the intended result of their work, but they started to think about how making a glass bead in this way could be useful. The technology to create glass beads at the time was similar to the manufacturing process used to make lead shot, where molten material was sprayed into droplet form and rapidly cooled using water. The technicians found that a grain of glass had been misplaced in the heating medium they were using, which then transformed itself from a granular form into a globular, near spherical shape. This inspired an idea as to how grains could be made into beads and how those beads could be used. Today, hundreds of thousands of tonnes of glass beads are used worldwide each year. The vast majority of glass beads are used in the road marking industry, within and on the surface of the thermoplastics and paints that make up the lines on the roads.
