Star Trek's Saw Bones. 6"x8" in 1/4" BB Ply with a black foam backer. I like the foam backer - very black, 2 mm thick, easy to cut, lots of other colors available from Hobby Lobby. $0.89 for 12"x18" 2 mm thick.
This was cut in a 2-deep stack with a #3 Crown Tooth blade. It is a slow cutter but was very good at making the sharp angles in the face. Easy to swing the blank through a 180? turn to cut both sides of a thin line.