Madeira Smocking Thread is a unique thread that reacts to heat. As you apply heat, the thread shrinks, gathering the fabric and creating a smocked effect. Use it for embroidery or decorative stitching. The thread shrinks but the fabric doesn't, causing a controlled puckering. The resulting wrinkled effect is beautiful and uses for it are limitless. No special iron or needles are required and the embroidery can be sewn on any type of embroidery machine. One spool per pack. 220 yards/200 meters.