The Alvin Self Healing Cutting Mat Kit is a professional quality mat that"s green on one side and black on the other. The printed grid pattern features .5-inch grid lines as well as guide lines for 45 and 60 degree angles. All four edges are fully numbered and graduated with 1/8-inch hash marks that extend beyond the zero base line. An art knife is included as well as replacement blades. About Alvin and Co. Alvin and Company has been a leading source of drafting and drawing supplies since 1950, and it continues to meet the evolving needs of its customers with value and innovation. The ever-expanding range of Alvin products includes papercraft, fine arts, hobby and craft, drafting supplies, drafting tables, and more. Alvin serves today"s needs - and tomorrow"s, too - for graphic arts, drafting, and fine arts products. Dedicated to the pursuit of excellence in all aspects of its business, Alvin relies on its employees to create and develop opportunities that set it apart from the competition. * Self healing surface always stays smooth * Mat made of 3mm thick vinyl composite * Printed grid lines and guides for 45 and 60 degree angles * Includes an art knife and spare blades * Mat measures 12L x 8.5W inches