Why 138 Bonded Nylon Sewing Thread is a Workshop Essential

If you're stepping up your game with heavy-duty projects like leather gear or thick upholstery, you've likely realized that 138 bonded nylon sewing thread is the heavy hitter you need in your bobbin case. It's one of those materials that, once you start using it, you wonder how you ever got by with the thin stuff. Whether you're a hobbyist making custom knife sheaths or a professional trimming out a car interior, this specific thread size hits a "sweet spot" that balances extreme durability with a look that actually pops on the finished piece. ...

May 3, 2026 · 7 min · Yuval Lietti