The basic knot stops thread from pulling through fabric

A knot at the end of your thread prevents the thread from sliding back through the fabric when you start sewing. Without it, your stitches come undone as soon as you pull the needle through. The most common method is the straightforward overhand knot — the same knot you tie in a shoelace, made small and tight at the thread's end.

You tie this knot before you start sewing, using just the thread itself and your fingers. It takes about five seconds once you know the motion. The knot sits on top of the fabric at your first stitch, then gets buried under your stitches as you sew forward.

Key Takeaways

  • An overhand knot at the thread's end prevents stitches from unraveling when you pull the needle through fabric.
  • Wrap the thread around your index finger, pull the working end through the loop, and tighten to create the knot.
  • The knot should be small and sit flush against the thread so it doesn't catch on fabric or create bulk.
  • If your knot is too large or loose, it will either show on the back of your work or slip through the fabric entirely.

Step-by-step: tying an overhand knot

Thread your needle first, then hold the needle in one hand and the thread in the other. Take the end of the thread (the end without the needle) between your thumb and index finger.

Wrap the thread around your index finger once, making a small loop. The working end of the thread — the part you just wrapped — should cross over the part of the thread that's still straight. Pull that working end back through the loop you just made, using your thumb and finger to guide it. Tighten by pulling the needle end of the thread while holding the knot steady with your other hand. The knot should slide down to the very end of the thread and sit tight.

Test the knot by tugging gently on both ends. It should not slip. If it does, the loop was too loose — untie it and try again, making sure you pull the working end all the way through before tightening.

Why knot size matters

A knot that is too large will either poke through lightweight fabrics or create a visible bump on the back of your work. A knot that is too small or loose will slip right through the fabric, and your stitches will come undone. The goal is a knot about the size of a small pea — large enough to catch on the weave of the fabric, small enough not to show.

If you are sewing on very delicate or loosely woven fabric, you can anchor the knot by taking a tiny stitch in place before you begin your actual seam. This gives the knot something to catch on. For heavy fabrics like denim or canvas, a standard knot works fine on its own.

What to do if the knot slips through

If you start sewing and the thread pulls through without catching, your knot was either too small or the fabric weave is too loose. Stop, pull the thread back out, and tie a second knot right next to the first one. Two small knots together are less likely to slip than one large one, and they still won't create much bulk.

Alternatively, take one small stitch in place before you begin your seam — just push the needle through the fabric and back out in almost the same spot. Then tie your knot and start sewing normally. The small stitch anchors the thread so the knot has something to grip.

Knots for different thread types

The overhand knot works for most thread — cotton, polyester, and blended thread all respond the same way. Slippery threads like silk or rayon can be trickier because they slide more easily. If you are working with slippery thread, make sure your knot is pulled very tight, and consider tying two knots instead of one.

For very thick thread or embroidery floss, a single overhand knot is usually enough because the thread itself is substantial. For thin thread, especially on delicate fabrics, err on the side of a slightly larger knot or a double knot — the extra security is worth the minimal bulk.

Removing a knot if you need to undo your work

If you need to remove stitches and start over, you will need to untie the knot at the end of the thread. Use a seam ripper or small scissors to carefully cut the knot away, or gently work it loose with the tip of a needle. Once the knot is gone, you can pull the thread out of the fabric. Tie a fresh knot at the end before you begin sewing again.

Do not try to pull the thread out without removing the knot first — you will damage the fabric or break the thread. Take the time to undo the knot properly, even if it feels tedious.

Frequently Asked Questions

Can I sew without a knot at the end?

No. Without a knot, the thread will pull straight through the fabric on your first stitch, and your seam will come undone. A knot is essential to anchor the thread.

What if I tie the knot in the middle of the thread by accident?

Cut off the knotted section and start over with fresh thread. A knot in the middle of your thread will jam in the needle or create a lump that catches on fabric as you sew.

Should the knot be on the front or back of the fabric?

The knot sits on the back (wrong side) of the fabric. When you push the needle through to start your first stitch, the knot stays on the back and gets buried under your stitches as you sew forward.

How tight should I pull the knot?

Pull it tight enough that it does not slip when you tug on the thread, but not so hard that you break the thread. A firm, steady pull is all you need — you should hear or feel a small click as the knot tightens.

Can I use a different type of knot?

The overhand knot is the standard because it is small, reliable, and quick. Other knots like a square knot or surgeon's knot are larger and unnecessary for hand sewing. Stick with the overhand knot unless you have a specific reason to use something else.