Sewing on a button that stays secure

A button that keeps coming loose is usually the result of one of three things: thread that is too weak for the job, a button sewn flat against fabric that is too thick for the buttonhole to close around, or a knot that was not secured properly on the back. Each is easy to correct. Use strong thread, leave a short thread shank so the button clears the layers, and finish with a secure knot on the reverse side.

The steps below cover choosing the thread and needle, stitching the button and finishing the work. They apply to standard two- and four-hole buttons, and to shank buttons that already have a loop on the back. The same principles apply to buttons on shirts, coats and trousers, although heavier garments need a more robust approach.

Choosing thread and a needle

For most garments, polyester thread is a sound choice because it is strong, resists abrasion and holds up well to repeated pulling. Cotton-wrapped polyester is also widely used and works well on natural-fiber garments. For heavy coats, jeans or workwear, a heavier thread or a thread designed for sewing on buttons gives a more reliable hold. Match the thread color to the button or the fabric, whichever makes the stitches less visible.

Cut a length of about 45 centimeters, or roughly 18 inches. A longer thread tends to tangle and wear thin from repeated passes through the fabric, while a much shorter one means frequent rethreading. Use a single strand for most buttons, and double the thread for large or heavy buttons on outerwear. A needle with a small eye that still passes through the button holes without distorting them works best. Knot the end of the thread securely before starting, and check that the knot is not caught in the fabric.

Before you start, confirm that the button sits where it should. Compare it with the buttonhole it closes, and check that the size is right: a button that is too large pulls the fabric open, and one that is too small slips through the buttonhole. If the buttonhole has stretched, the button may never stay firm, and the buttonhole may need its own repair first.

If the old button left frayed threads behind, remove the remnants before resewing. Pull out the old thread, check the fabric around the former holes, and reinforce it if it has torn. Starting from a clean base keeps the new stitches from catching on old, weakened fibers.

Avoid thread that is very fine, stretchy or old. Fine thread can break under the pull of a buttoned closure, elastic thread can relax after a few wears and leave the button loose, and thread stored for years, especially in a damp place, becomes brittle. Starting with a fresh spool of strong thread is a small step compared with resewing a button several times.

Sewing the button and making a thread shank

Mark the button position with a pin or a fabric marker, making sure the button lines up with the buttonhole it closes. Place the button on the marked spot, and lay a toothpick, a matchstick or a large pin across the top of the button. This spacer creates the gap that a thread shank needs. Bring the needle up from underneath, pass it through one hole, then down through the opposite hole, and repeat through each hole four to six times. Each pass should be snug but not pulled so tight that the fabric puckers.

For a two-hole button, sewing the stitches parallel gives a simple, strong hold. For a four-hole button, sewing parallel pairs or crossing the thread in an X are both common and both work, as long as the same pattern is used for every pair of holes. Remove the spacer after the final pass through the holes. Bring the needle up through the fabric only, so it comes out between the button and the fabric. Then wrap the thread several times around the stitches between the button and the fabric, forming a short shank. Three or four wraps are usually enough for a standard button. Finally, take the needle back through the fabric to the reverse. The shank lets the button sit above the fabric so the buttonhole can close without straining the threads.

Shank buttons, which have a loop on the back, need a different approach. The loop already holds the button away from the fabric, so it does the job that a thread shank does on a flat button. Sew through the loop several times rather than wrapping thread around the stitches, keeping each pass snug but not so tight that the fabric puckers. Then secure the thread on the reverse as described below.

Securing the knot on the reverse

With the needle on the reverse of the fabric, directly beneath the button, make a few small stitches through the fabric and the threads beneath the button to anchor the thread. Keep these stitches tight and neat, then finish with a knot. Two or three small backstitches or a knot tied against the fabric is standard. Trim the thread close to the knot.

On heavy outerwear, buttons take a lot of pull, so it helps to add a small square of interfacing or a fabric patch under the button before stitching, which spreads the stress across a larger area. On thin fabric, the same reinforcement helps stop the button from tearing through the garment. Test the finished button by giving it a gentle tug in several directions. The stitches should feel firm, while the button stands slightly off the fabric on its thread or built-in shank, so the buttonhole closes smoothly. Check the stitching again after the first few wears, particularly on coats and jackets, because the tension may settle as the garment is worn.