What is the Upper Thread?
The upper thread (commonly called the “needle thread”) is the thread that passes from above through the needle of a sewing or embroidery machine, then runs through the fabric and gets caught by the bobbin or hook system to form stitches. Understanding the upper thread path and its correct tension is essential for reliable stitching.
Features & Use
- Properly adjusted upper thread tension ensures the lower thread does not show on the top side of the fabric and that stitches are reaching the correct depth.
- Threading the upper thread correctly — including through any tension discs, take-up lever, needle eye — is crucial; skipping a guide can lead to loops or thread breakage.
- The material, thickness and type of upper thread influence settings: heavier threads may need different tension or backing in embroidery to keep the stitch flat and prevent puckering.
Notes & Tips
- If you see the bobbin thread (under-thread) on the surface, your upper thread tension may be too high – loosen the upper thread tension.
- If you see upper thread loops on the underside, the upper thread tension may be too low. Adjust accordingly.