Probably not resin, but rather broken glass fibers. I can't remember the term exactly, but "pick" somehow sticks in my head. Nodules was probably the simpler term. I know the glass cloth manufacturer's screen for excessive levels of it, but it can also be developed during resin impregnating with too much line tenison. Should disappear with lamination. Glenn -----Original Message----- From: Timothy Reeves [mailto:[log in to unmask]] Sent: Friday, September 21, 2001 9:56 AM To: [log in to unmask] Subject: [TN] Prepreg nodules Could any prepreg/laminate manufacturer out there (or other knowledgeable soul) explain what could cause little bumps or nodules on the surface of prepregs and why -if they are just resin- they don't melt completely and leave no evidence of their existence on the laminated board? Tim Reeves ECD