For use with rayon and other specialty machine embroidery threads including polyesters. The special scarf, long smooth groove, and large eye, of this needle protect these more fragile threads and guard against excess friction. These needles come in size 75. The beautiful sheen of these threads results in outstanding embroidery work. Check the size of the thread and use the appropriate size needle for each thread — remember the finer the thread, the smaller size needle that should be used.