Greetings, I have run 2 analyses with BT thickness of 15mil and 24mil while all other variables the same. There is a huge difference in predicted CMF. For 15mil BT, CMF is 2812; for 24mil BT, CMF is 12118. I did not expect such big difference even though I expected good increase by using 24mil BT. I don't have experimental data to verify my data now. So I like to listen to your opinions. What is your take here? Is is possible that such a big difference could exist by just changing BT thickness from 15 to 24 mils? Best regards, Yuan Li ################################################################ 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 ################################################################ ################################################################ 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 ################################################################