Home › Embroidery › Embroidery Bobbin Thread Guide: Weight, Styles & Bobbin Showing on Top
Short answer: Most commercial machines use L-style (smaller) or M-style (larger) pre-wound bobbins with a fine 60–90 wt polyester bobbin thread. Magnetic and sideless bobbins feed more evenly and run longer. If bobbin thread shows on top of your design, the top tension is too tight or the bobbin tension too loose.
| Style | Fits | Notes |
|---|
| L-style | Most single- and multi-head machines incl. many Happy models | Most common |
| M-style | Larger rotary hooks | Holds more thread, fewer changes |
| Paper-sided | Standard | Madeira 308-503 |
| Magnetic | Smoother feed, less backlash | Madeira 308-509 |
Bobbin thread showing on top?
- Loosen the top tension a little.
- Check bobbin tension with a drop test or the H/I tension test.
- Clean lint from the bobbin case and hook.
- Rethread the top — a missed guide causes tight top tension.
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FAQ
What weight is embroidery bobbin thread?
Usually 60–90 wt polyester — much finer than the 40 wt top thread.
L or M bobbin?
Check your machine manual or bring the bobbin case in — we can match it in Tempe.
Are magnetic bobbins worth it?
For production shops, yes — more even tension and less thread waste.
Can I use top thread in the bobbin?
No; it is too thick and causes bulky backs and tension problems.
Talk to the embroidery team at Buckets of Ink — Tempe, AZ, since 1981. Authorized Madeira and Happy Japan dealer. Ask about our discounts, starter supply packages and great financing on Happy machines — we'll help you get into your next machine.
Build a quote · Call
(480) 229-7806 · Showroom: 906 S Priest Dr, Suite 101, Tempe AZ 85281 (local pickup + free weekly Phoenix-metro delivery on supply orders).
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