Thread spools are cylindrical devices that hold and organize sewing thread. They come in various sizes and materials, such as plastic or wood, and are designed to keep the thread from tangling or unwinding. Spools are essential for both hand sewing and machine sewing, providing a convenient way to manage the thread supply. Typically, a spool has a central core that allows it to fit onto a sewing machine or be easily handled during hand sewing. The thread is wound around the spool in a specific direction, ensuring smooth dispensing when sewing. Properly storing thread spools helps maintain the quality of the thread and prevents damage.