White Bobbin Thread. This very fine, soft spun, extremely strong bobbin thread is specifically weighted for use with computerized embroidery designs When embroidering will reduce bulk, Developed for optimal use on high speed computerized embroidery machines Virtually eliminates your tension problems, Bobbinfil can actually help your machine embroider and sew more smoothly So fine you can get twice as much on your bobbin 70 wt. 2 ply 100% polyester