ThreaDelight ™ Bobbin 60WT Polyester Embroidery Thread Kit - 10 cones 1100 yards each. White.ThreaDelight ™ 60wt polyester bobbin thread is the perfect thread for winding your own bobbins or to be used as an "Endless Bobbin" for Singer XL6000/5000.ThreaDelight ™ 60wt thread also can be used as a top thread for thinner and more delicate results for your embroidery project. 60wt polyester thread is the best choice for lace designs or small lettering embroidery.