Janome 1100D - Manual (Page 59)

58
2-Thread Overcast
Balanced Tension
The needle thread should resemble a straight stitch on
the topside (1) of the fabric. It will lock with the lower
looper thread on the fabric edge. The needle thread
should lie flat in a V-shape on the fabric underside (2).
The lower looper thread should lie flat on the topside of
the fabric and lock with the needle thread on the fabric
edge.
The needle thread is too loose.
If the needle thread (a) is pulled up over the fabric
edge to the topside of the fabric, increase the needle
thread tension and/or decrease the lower looper thread
tension.
(2)
(1)
(a)