Pfaff 2170 - Manual (Page 58)

Sewing
3:17
Buttonhole with gimp thread
Buttonholes that are sewn with gimp threads are more stable, durable
and has a professional appearing. Use pearl cotton or a regular gimp
thread.
1. Insert the Sensormatic buttonhole guide.
2. Place the center of a length of gimp thread over the metal bar
extending from the center back of the buttonhole foot. Pass the
thread ends under the foot and pull up into the right and left
guides on the front of the presser foot.
3. Attach the buttonhole foot. Before starting to sew, pull it backward
as far as the second red mark.
4. After completing the buttonhole, pull the ends of the gimp thread
until the loop of thread is hidden below the buttonhole bartack.
5. Thread the gimp threads into a needle and pull them to the wrong
side of the garment. Tie the gimp threads and cut off the excess
thread.
Eyelet buttonhole with gimp thread
1. Insert the Sensormatic buttonhole guide. Place the center of a length
of gimp thread over the metal bar extending from the center front
of the Buttonhole foot. Pass the thread ends under the foot and pull
up into the right and left guides on the back of the presser foot.