TxDOT requires that beads be manufactured to conform to . Three types of bead gradations are specified under DMS 8290 and are tested using . Type I beads are the smallest of the three types and are used only as intermix beads for thermoplastic. Type II beads are commonly referred to as “Texas standard” beads because they have historically been the typical drop-on beads used by TxDOT for many years. Type III beads are drop-on beads of a larger gradation. Type III beads are relatively new to the market and are marketed for their ability to provide wet-night visibility under certain conditions. Check with TxDOT’s Materials Laboratory for approved use of each bead type.