Again, but I love this stuff, you don't need two ply constructions except when you need them. You get very well balanced structures, from a resin to glass ratio point of view, with single ply preg and core material except when using 7628 types/styles. You never use this facing copper as it only has about 43% resin content and you may very well find starvation using it. I feel like I've written this before. Anyway, 2113 and 2116 glass styles offer the best of both laminate integrity (plenty of resin) and dimensional stability (plenty of glass). No problem using two plies of these types in whatever requirement. Two plies of 106 or 1080 isn't appropriate, if avoidable, because it's two resin rich and makes everything slip and slide in the press and that's a mess. As for the shorting issues, that's been resolved even by the military/aerospace folks for years. How many, I can't even remember. If you've seen this condition, as voiding and shorting etc., get a photo for us all to see. If proof exists, it has to be a billion to one shot and certainly would point to possible process control problems of an other than preg issue. MoonMan --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------