I'm surprised to not see any feedback on this at all! My take is this External layers or any layer that's mixed wiring/plane you need to use positive shapes. Dynamic is best as you don't have to update each time you change something in that area. Inner layers that are fully plane (may be multiple planes, just no traces) are best done with negative planes. Allegro database and output data files are smaller. From: icu-pcb-forum-bounce@xxxxxxxxxxxxx [mailto:icu-pcb-forum-bounce@xxxxxxxxxxxxx] On Behalf Of Zafar Bhatti Sent: Thursday, July 24, 2008 6:19 PM To: icu-pcb-forum@xxxxxxxxxxxxx Subject: [PCB_FORUM] Planes be POSITIVE or NEGATIVE Hi All, What is the preferred way to make planes, positive or negative, dynamic or static. Any thoughts, insights would be deeply appreciated. Any pros / cons for both cases? Regards, Zafar Bhatti Design Engineer Whizz Systems Inc. Office:(408) 980-0400 Ext. 112 Cell:(408) 569-0517 zbhatti@xxxxxxxxxxxxxxxx <mailto:zbhatti@xxxxxxxxxxxxxxxx>