SINGER 14T967DC-WORKBOOK QUANTUMLOCK - Manual (Page 111)

Four-Thread Ultra-Stretch Mock Safety Stitch
The Four-Thread Ultra-Stretch Mock Safety Stitch is stronger than the Three-Thread
Ultra-Stretch Mock Safety Stitch. The additional thread provides added strength to
the seam and is good choice for knits as well as wovens. This stitch works well when
applying ribbing to a garment. Ribbing is often seen on cuffs, collars and waistbands
of active wear. This stitch requires two needle threads and two looper threads.
Four-Thread Ultra-Stretch Mock Safety Stitch page 1