The straight stitch is the most frequently used utility stitch on a sewing machine. The needle moves vertically without swinging side to side. On most domestic machines, the visible line is produced as a lockstitch, in which the upper thread and bobbin thread interlock between the fabric layers.
Straight stitch and lockstitch are not exact synonyms
“Straight stitch” describes the path seen on the fabric. “Lockstitch” describes how two threads form the stitch. Industrial chainstitch machines can also create a straight-looking line using a different thread formation. Conversely, a domestic lockstitch mechanism can form zigzag and decorative patterns when the needle moves sideways.
A running stitch is a separate hand- or embroidery-stitch concept. The existing article on running stitch explains its use for embroidery outlines rather than treating it as a synonym for a machine lockstitch.
Typical uses
- construction seams in non-stretch woven fabric
- hems and visible topstitching
- zipper insertion
- temporary machine basting at a long stitch length
- reinforced stitching with a triple straight-stitch program
A regular straight stitch has little stretch. Used across the greatest stretch of a knit, it may snap when the fabric is pulled; a stretch stitch or overlock construction is generally more suitable.
Choosing stitch length
Normal construction commonly uses a medium setting. Fine fabric may need a somewhat shorter stitch, while thick fabric and visible topstitching often look better with a longer one. Very short stitches can perforate delicate material and are difficult to remove. Basting uses a much longer length for easy removal.
Test the combination on a scrap with the same layers, needle, and thread. Balanced thread tension keeps the interlocking point from being pulled clearly to either surface.