The basic finish knot: pull tight and lock it in place
A finished sewing knot is a small knot you tie at the end of your thread to keep stitches from unraveling. The most common method is to tie a straightforward knot close to the fabric, then pull the thread tight so the knot sits right at the surface where your last stitch exits. This locks the thread in place and prevents the entire seam from coming loose.
To do this, bring your needle to the back of the fabric after your final stitch. Make a small loop with the thread, pass the needle through it, and pull tight. The knot should sit flush against the fabric, not floating above it. If the knot is too loose or too far from the fabric, it will slip through and your seam will fail.
Key Takeaways
- A finished knot sits at the surface of the fabric where your last stitch exits, not floating above it or buried inside.
- The most reliable method is a straightforward overhand knot pulled tight, followed by a second knot for extra security on seams that will see stress.
- Burying the knot inside the fabric by running the needle through a fold or seam allowance hides it and protects it from snagging.
- Different fabrics and seam types may need different knot styles — a single knot works for lightweight cotton, but heavy fabrics and stress seams need double knots.
- A knot that slips or comes undone usually means the thread was not pulled tight enough or the knot was tied too far from the fabric.
The double knot for seams under stress
If your seam will bear weight or movement — a bag strap, a button attachment, or a hem on pants — tie two knots instead of one. After you tie the first knot and pull it tight, make a second loop with the remaining thread and tie another knot directly on top of the first. This doubles the holding power and makes it much harder for the thread to slip.
Pull each knot equally tight. A loose first knot will slip even if the second one is tight. The two knots should sit so close together they look like a single thicker knot at the fabric surface.
Burying the knot inside the fabric for a hidden finish
For visible seams where you do not want the knot to show, run the needle through a fold in the seam allowance or through the layers of fabric before tying the knot. Bring your needle out through the fold, make your knot, and then pull the thread so the knot slides inside the fold. This hides the knot completely and protects it from snagging on other fabric or catching on skin.
This method works best on seams where there is extra fabric to hide the knot in — hems, seam allowances, or the inside of a bag. On thin fabrics or flat seams with no fold, a surface knot pulled tight is more reliable because there is nowhere safe to hide it.
Why your knot keeps slipping
A knot that comes undone almost always means one of two things: the thread was not pulled tight enough when you tied the knot, or you tied the knot too far from the fabric. If there is slack between the knot and the last stitch, the thread can work its way loose over time, especially if the seam moves or stretches.
To fix this, pull the thread as hard as you safely can without breaking it when you tie the knot. The knot should be so tight it is hard to undo by hand. If you are using delicate thread that breaks easily, use shorter lengths so you have less thread to manage, and tie the knot closer to the fabric so there is less room for it to slip.
Knot styles for different fabrics
Lightweight cotton and linen hold a single tight knot well because the fabric is dense enough that the knot cannot slip through easily. Heavier fabrics like denim or canvas also hold single knots, but they benefit from a double knot because the seams carry more stress.
Stretchy fabrics like jersey or knit need extra caution. Tie a double knot and bury it if possible, because the fabric itself moves and can work a loose knot free. Slippery fabrics like silk or satin are the hardest to work with — a single knot can slip through the weave, so always use a double knot and pull it as tight as you can.
Finishing thread ends after the knot
Once your knot is tied and locked in place, trim the thread close to the knot with scissors. Leave about one-eighth inch of thread above the knot so it does not unravel, but not so much that it sticks out and catches on things. On visible seams, trim even closer so the thread end is barely visible.
If you buried the knot inside a fold, you can trim the thread flush with the fabric because it is hidden. On a surface knot, leave a tiny bit of thread so the knot has something to grip and cannot slip back through the fabric.
Common mistakes that weaken the knot
Tying the knot too far from the fabric leaves slack that allows the thread to slip. The knot should be touching the fabric or sitting in a fold, not floating above it. Another common mistake is using too much thread — long lengths are harder to control and more likely to tangle or slip. Cut your thread to about 18 inches for hand sewing, which is long enough to work with but short enough to keep tight.
Pulling the knot too gently is also a problem. Many people tie a knot and then move on without pulling it truly tight. Spend an extra second pulling the thread hard so the knot is as small and firm as possible. A firm knot is much less likely to slip than a loose one.
Frequently Asked Questions
Can I tie a knot in the middle of a seam if I run out of thread?
Yes. Tie a knot, bury it in the seam allowance or fold if possible, trim the thread, and then start a new thread with a knot of its own. Overlap the stitches by about half an inch so the two sections lock together. This is stronger than a single long seam with a knot in the middle.
What if my knot keeps coming undone even when I pull it tight?
The thread may be slipping through the fabric weave, especially on silk or satin. Try a double knot instead of a single one, or bury the knot inside a fold. If the thread itself is old or damaged, replace it — old thread loses grip and frays easily.
Should I wax my thread to make the knot hold better?
Waxed thread does hold knots more securely because the wax adds friction. It is not necessary for most sewing, but it helps on stretchy fabrics or seams that will see a lot of movement. You can buy pre-waxed thread or run regular thread through beeswax before sewing.
Is it better to tie a knot or use a backstitch to find the thread?
A knot is faster and more reliable for hand sewing. A backstitch (sewing back over your last few stitches) works but takes longer and uses more thread. Most hand sewers use a knot at the start and end of a seam, with a backstitch only on seams that will see heavy stress.