Crewel needles are specialized sewing needles designed for embroidery, particularly for working with crewel wool. They have a long, slender shaft and a larger eye, allowing for easy threading of thicker yarns. The pointed tip helps pierce through fabric, making them ideal for various embroidery techniques. These needles come in different sizes, catering to various thread thicknesses and fabric types. Using the right size ensures smooth stitching and prevents damage to the fabric. Crewel embroidery often features intricate designs, and the appropriate needle is essential for achieving the desired results.