Baby Lock Evolve (Previous Model) (BLE8W) Instruction and Reference Guide - Manual (Page 36)

Flatlock seams are most suited to fabrics which do not ravel such as
interlock knits, tricot, sweatshirt fleece and synthetic suede. The
needle thread is carried below the fabric and to the cut edge of the
fabric. The lower looper thread rides along the cut edge of the fabric
for stability. The edges pull open and flatten within the stitch for a
non-bulky join (fig. A). Be sure to sew a test sample first to determine
whether the stitch will have the strength to hold the seam without the
fabric pulling away.
Move the stitch selector lever to "D".
For the O-2 needle 3-thread flatlock, follow the suggested settings
and the threading diagram below.
O
V
E
R
L
O
C
K
S
T
I
T
C
H
E
S
E
X
P
R
E
S
S
34
3-Thread Flatlock - Narrow
A
NEEDLES
O-2
LENGTH
2 - 3
WIDTH
3.0 - 3.5
STITCH
SELECTOR
D
WAVE
SELECTOR
O