What you are probably observing is data not accurately reviewed by the fabricator prior to publishing or presenting the information. This may be due to out-dated information being made available in company literature, typo, misunderstanding of the information being written, etc etc. The Dk may indeed vary from fabricator to fabricator as well as from lot-to-lot at the same fabricator but not to the degree you posted. This variance is just inherent to most laminate fabrication processes. If there is a specific characteristic of the laminate that you just absolutely need to fall within tight tolerances it is a good idea to have the specific lot tested prior to use, after fabrication, assembly, etc in order to determine the actual value of the lot or product at that moment. Take the literature you receive from the fabricator with a grain of salt, ask questions, and don't worry if the number varies slightly. Franklin --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------