This 12" x 18" green, self-healing cutting mat (11" x 17" grid) is double sided and offers the convenience of imperial measurements on one side and metric on the other. 3 ply green mat. Double sided - imperial on one side, metric on the other. Protects cutting surface and extends the life of cutting tools. Convenient 30°, 45° and 60° markings on the imperial side of the mat.