Waxing Thread for Handsewing Leather

Sometimes when making leather goods for production, I feel the crunch of deadlines and spend way too much time on a piece for what we’d like it to cost. Like any business, it can be long hours and hard on the body. There are parts of this craft, though, that can seem like a little break in the day. Waxing thread is one of those things. Perhaps it’s because it’s one of those small prep tasks that help more than it seems, or because it’s so routine, like putting on an apron.

Waxing your thread before handsewing helps to smooth it down, so it can pass more easily through the stitch holes. You abrade the thread as you handle it, tugging on it and running it roughly through the seams. The wax serves as a protective layer to prevent the thread from deteriorating. It keeps the oils from your fingers (or from your recent lunch) from dirtying up the leather.

Our MBT polyester thread already has an in-bonded coating in the center of the thread to keep it together.  Adding wax combines an outer layer with the inner bonded core to strengthen the thread further. Similarly, our waxed linen thread is a retwisted thread that already has wax on it.

Regardless of the thread you use, the goal is to have a moderately waxed thread. It shouldn’t be too sticky. Some thread is already slathered with a soft wax, so adjust the amount accordingly. I use beeswax, which is firmer. Wax the thread about four times; I start with the portion of the thread that I’m holding and then do the rest. There’s a squeak that happens when you’ve coated the whole thread.

One other thing I do is heat the wax. Mr. Niwa first showed me this technique, and I use it regularly. This melts the wax into the thread, giving it a more wire-like feel and slightly darkening the color to mellow it out. You can use a heat gun or even a simple hair dryer will do the trick. Be careful not to linger too much with the heat, especially on the synthetics. Otherwise, they will melt just like when finishing the thread ends.

This week I made a short video waxing about waxing your thread.