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.