Rotary Cutting BladesRotary cutter blades are sharp, circular steel blades used in sewing and quilting for precise, clean cuts through fabric, often slicing multiple layers at once for efficiency, with common sizes like 45mm (standard), 60mm (heavy duty), and smaller 28mm 18mm for curves, requiring regular replacement when dull for safety and best results, and sometimes coated (like titanium) for extra durability and sharpness.