Slate studios acoustic designer Teale Haley has perfected some traps made of rigid fiberglass with air gaps built into the frames so that they don't have to have them as far off the walls which to me always looked a bit strange. He can also do custom sizes and just about any color you can imagine, just ask. He's installed them into a lot of studios here in LA and everyone has been ecstatic. They are not expensive either.. See pics here:
http://www.slatestudios.com/sales4.html