Hi Larry - We use a materials note that reads somewhat as follows: # Fabricate goard from laminates and bonding materials conforming to IPC-4101/**. Nominal starting copper is 1/2 ounce [153 G/M2] on layers *, *, *, *, *, * and 1 ounce [306 G/M2] on layers *, *, * and *. [Cladding type, if critical, is also spelled out in this note using IPC4101 table 1]. The specifics of layer to layer spacing, allowable etch factors, etc., are all detailed elsewhere in the drawing notes. Hope this helps - Kelly ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################