Self-healing, double-sided convenient size for all crafting On one side 12" x 18" green self-healing professional quality rotary mat especially designed for use with OLFA rotary cutters is a convenient size for taking along. Double-sided with yellow grid lines on one side for precision cutting, solid on opposite for general cutting. Rotary mats protect your work area and greatly extend the life of your rotary blades. 1.5mm thick for a variety of applications. The other Side is a Self-healing, professional quality rotary mat Double-sided use with a metric grid (30cm x 45cm) on one side. especially designed for use with OLFA rotary cutters. 1.6mm thick. Store flat.