found an answer, 59.6 X 10^6 but the tool has a default value to 595900, I guess that will have to do. -----Original Message----- From: sjchar3@xxxxxxxxxxxx To: icu-pcb-forum@xxxxxxxxxxxxx Sent: Tue, 16 Oct 2007 2:15 pm Subject: [PCB_FORUM] hopefully question isn't silly Group: Setting up "Layout Cross Section" and the top layer is 1 oz copper. In the same row it asks for conductivity, dielectric, loss tangent. Anyone know the loss tangent for copper? Sam Check Out the new free AIM(R) Mail -- Unlimited storage and industry-leading spam and email virus protection. ________________________________________________________________________ Check Out the new free AIM(R) Mail -- Unlimited storage and industry-leading spam and email virus protection.