Prepreg is a bonding material used in the fabrication of multi-layer PCB boards, which, after curing, has the same properties as the core /base layer materials. Prepregs have various glass styles 106, 1080, 3313, 2116 and 7628 used by board fabricators. Board fabricators use a variety of prepreg glass styles. These styles include 106, 1080, 3313, 2116 and 7628. Limitations may apply to the number and types of prepreg, so it is best to contact a Hopetimepcb representative for further details.