eZthings Heavy Duty Utility Knives and Blades Set for Cutting Arts and Crafts Projects (Cutter Blades) eZthings Heavy Duty Utility Knives and Blades Set for Cutting Arts and Crafts Projects (Cutter Blades) 18 MM - 0.7 Inch Utility Knife Set for Cutting Fabric, Leather, and Raw Materials. Heavy Duty Industrial Graphic Knives for Upholstery, and Composite Materials. 2 Utility Knives + 18 MM Blades Set for Cutting Leather Crafts and Arts. Quality Work Blades for Hobby or Commercial Use.