SINGER 8280 Prélude - Manual (Page 47)

GB
40
Straight stitching
0
1
2
3
4
4 3 2 1 0.5
Turn the stitch selection dial so that the pointer is set to the
straight stitch position.
Generally speaking, the thicker the fabric, thread and needle,
the longer the stitch should be. For a fine stitch set length at "1"
or "2". For gathering set stitch length to "4".