Metallic thread breaking usually comes from too much tension, wrong needle, or speed issues. First, loosen your top tension dramatically to 1.0 (yes, that low). Metallic thread is less elastic than regular thread and can't handle tight tension. Second, use a Topstitch #90/14 needle with a large eye and deep groove that protects the delicate metallic fibers. Third, slow down your stitching speed. Metallic thread shreds when pushed through fabric too quickly. Finally, use a vertical spool pin so the thread unwinds smoothly. With these adjustments, metallic thread transforms from frustrating to fabulous.