Loops, knots and puckers: fixing thread tension
Most "tension problems" are really threading problems. Rethread first, then adjust the top tension one number at a time.
Pinny's tip
Rethread the top thread with the presser foot UP. With the foot down, the tension discs are closed and the thread misses them.
Rethread the top thread with the presser foot UP. With the foot down, the tension discs are closed and the thread misses them.
What you'll need
- Scraps of your project fabric: folded double, for test lines.
- Two thread colours: one on top, one in the bobbin, so you can see which is misbehaving.
- Your machine manual: for its default tension setting.
Step by step
- Switch off, raise the presser foot, and rethread the top thread completely.
- Take the bobbin out, check it is wound evenly and put it back the way the manual shows.
- Fit a fresh needle of the right type and size.
- Sew a test line on a double layer of scrap, with different colours top and bottom.
- Loops of top thread on the underside: top tension is too loose, or the top thread is mis-threaded. Rethread, then turn the dial up a step.
- Bobbin thread showing on top, or puckering: top tension is too tight. Turn it down a step.
- Test again after each change. Leave the bobbin case screw alone unless your manual or dealer says otherwise.
Watch
Thread Tension & Troubleshooting | Sewing Machine Basics (5:34)
By Paige Handmade · Open on YouTube
Chosen from its title and channel: a 5-minute video from Paige Handmade on the same topic as this guide. Embedded from YouTube with credit; we don't host it. It only loads when you press play.
Read your stitches
| What you see | What it usually means |
|---|---|
| Messy loops underneath (“bird’s nest”) | Top thread missed the tension discs: rethread with the foot up |
| Bobbin colour dots on top | Top tension too tight |
| Top colour dots underneath | Top tension too loose |
| Skipped stitches | Wrong or worn needle |
Watch it done
- Thread Tension & Troubleshooting | Sewing Machine Basics by Paige Handmade on YouTube. Opens on YouTube; the video belongs to its creator.
Sources
All checked 1 November 2026. We read these; we did not test the products ourselves.