These self-healing and reversible cutting mats are 3mm thick and extra durable. Made from a unique composite vinyl material designed for both rotary blades and straight utility blades, they provide a long-lasting, non-glare surface that can be cut and slashed constantly without showing marks or cutting lines. Can also be used as a desk blotter or general-purpose work mat. Hanging hole for convenient storage (except 3½ x 5½ size). GBM series is green on one side, black on the other, both sides with grid lines.