A great thread for very fine and delicate fabrics, embroidery bobbin and pucker free seams. Provides consistent thread tension for optimum interlacing of the upper and bobbin threads. Recommended Needle Size: 60/8 & 70/10. Mettler Bobbinette Thread, formerly Bobbin Fil thread, 1094 yard spool. 100% Polyester. Color Black 4000.