METTLER-Bobbin Fil 1094 Yards. For very find and delicate fabrics and pucker free seams, as well as for high quality serging. Bobbin Fil is especially good as bobbin thread. Due to its core spun construction, it is very tear-resistant. Suitable for commercial sewing and embroidery machines. 100% Polyester. This package contains one 2-1/4 inch spool of bobbin fil with 1094 yards. Available in black or white, each sold separately. Imported.