Thermoplastic markings are applied using specially designed vehicles. Usually, thermoplastic marking mode should apply with equipment called a road marking machine to coat traffic lines, and the road paint needs preheating by a device commonly called a preheater. The thermoplastic mix is heated in trucks to about before being fed to the application apparatus. This is often a screed box or ribbon gun. Immediately after the thermoplastic has been applied, glass beads are laid onto the hot material so that they embed before the plastic hardens. These beads provide initial retroreflection. As the marking wears during use and the initial beads are lost, the beads mixed with the binder are uncovered, providing long term retroreflectivity. These can be made exceptionally thick to produce a rumble strip effect.