Baby Lock Diana (BL480A) Instruction and Reference Guide - Manual (Page 58)

Lower looper thread
Needle thread
Underside
Upper looper thread
Topside
Needle thread
A flatlock stitch is achieved by adjusting the tension of the 2-thread
or 3-thread overlock stitch, sewing the seam, and then pulling the
fabric apart to flatten the seam.
The flatlock stitch can be used as a construction and decorative
stitch or for ornamentation only.
Use either overedge right needle or left needle.
Begin with the machine threaded and tension balanced for the
2-thread overlock (page 41) or 3-thread flatlock stitch (page 43).
Place the fabric wrong sides together to sew a decorative stitch
on the right side of the garment.
Sew the seam, trimming the excess fabric.
The needle thread (Red or Yellow) will form a V on the underside
of the fabric.
The lower looper thread will pull into a straight line at the fabric
edge.
Pull on opposite sides of the seam to pull the stitches flat.
27. STITCH VARIATIONS AND SEWING
TECHNIQUES
Machine Set Up
Flatlocking a Seam
How to Sew a Flatlock Decorative Seam
57