Sure agree with the "old timer." 2 oz stuff was light weight in a time past. Getting 4 core/preg to do its thing now is different. Using single ply constructions as 2113 or 2116 provides exceptional dimensional stability in all axes including minimizing warp and twist - for a number of reasons. These materials also are well balanced in terms of resin to glass ratios. Because of this alone, they may not "fill" well enough to provide consistent initial quality and long term reliability. Using miltiple core/preg materials offer an answer to the "fill" issue. However, they cost more in many areas. 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 the following message: SET Technet NOMAIL 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 ---------------------------------------------------------------------------------