Ending a stitch means securing the thread so it won't unravel
When you reach the end of a seam on your sewing machine, you need to lock the thread in place so your stitches don't come loose. The most common way is backstitching—running the machine backward over the last few stitches you just made. This creates a knot at the end of the seam without you having to tie anything by hand. Most machines have a reverse button or lever that lets you do this in seconds.
If your machine doesn't have a reverse function, or if you prefer a different method, you can tie off the threads by hand instead. Both approaches work; backstitching is just faster and more reliable for everyday sewing.
Key Takeaways
- Backstitching—pressing the reverse button and sewing backward for three to five stitches—is the standard way to lock thread at the end of a seam.
- You should backstitch at both the beginning and end of every seam to prevent unraveling.
- If your machine has no reverse function, you can pull the threads to the back and tie them in a knot by hand instead.
- Trim the thread tails close to the fabric after you finish, leaving about a quarter-inch so they don't slip back through.
How to backstitch on a standard sewing machine
Locate the reverse button or lever on your machine—it is usually near the presser foot or on the side of the machine body. Check your manual if you cannot find it; the location varies by brand and model. Once you have found it, sew forward to the end of your seam as normal, then press and hold the reverse button while you continue sewing backward over the last three to five stitches you just made.
Release the reverse button and sew forward again to return to your normal direction. You have now locked the thread. The backward stitches overlap the forward ones, creating a knot that holds everything in place. This takes only a second or two and is much faster than hand-tying.
Tying off threads by hand if your machine has no reverse
If your machine does not have a reverse function, or if you prefer to hand-tie, pull both the top thread and the bobbin thread to the back of the fabric. Leave about three inches of thread hanging. Remove the fabric from the machine and lay it flat on a table.
Cross the top thread over the bobbin thread and pull both tight to form a knot close to the fabric. Trim the tails to about a quarter-inch from the knot. This method is reliable but takes longer than backstitching, so most people use it only when backstitching is not an option.
Why you need to find both ends of a seam
A seam that is not locked at the beginning and end will gradually unravel as the fabric moves and stretches. This is especially true for garments that get washed and worn often. Backstitching at the start of a seam is just as important as backstitching at the end—many people forget the beginning and wonder why their seams fall apart.
If you are sewing something that will not move much—like a decorative stitch on a pillow cover—skipping the lock is less risky. But for any seam that bears weight or stress, locking both ends is the only way to make sure your work lasts.
Trimming thread tails without damaging the seam
After you have backstitched or tied off, use scissors to trim the thread tails. Cut them as close to the fabric as you can without cutting the fabric itself—a quarter-inch away is a safe distance. If you leave the tails too long, they can catch on other threads and pull the knot loose. If you cut them too short, the knot may slip back through the fabric.
For delicate fabrics like silk or chiffon, trim even more carefully. A small snip in the wrong place can create a run or hole. If you are nervous, leave the tails a little longer than you think you need to; it is easier to trim more than to fix a cut.
Special cases: Corners, curves, and thick seams
When you reach a corner, backstitch before you lift the presser foot and pivot the fabric. This locks the stitch at the corner so it does not come apart when the seam bends. Curves work the same way—backstitch at the end of the curved section before you move on to the next part of the garment.
For thick seams (like when you are sewing through multiple layers of denim or canvas), backstitching may be harder because the needle has to push through so much fabric. If your machine struggles, try backstitching for only two or three stitches instead of five. If the machine still stalls, switch to hand-tying instead. Some machines also have a "needle down" setting that keeps the needle in the fabric while you pivot or reverse, which can help with thick materials.
Frequently Asked Questions
Do I have to backstitch if I am going to sew over the same seam again?
No. If your next seam will cross over the end of this one, the overlap will lock it for you. But if there is any gap between seams, backstitch anyway. It only takes a second and prevents surprises later.
What if I forgot to backstitch and the seam is already coming loose?
Pull the fabric tight and look at where the stitches are coming out. If only a few stitches have unraveled, you can hand-sew them back down with a needle and thread. If more than half an inch has come loose, it is usually faster to cut out that section and resew it.
Can I backstitch on a serger or overlock machine?
Most sergers do not have a reverse function. Instead, tie off the thread tails by hand or use a serger thread chain—a small loop of thread that locks the stitches. Check your serger manual for the correct method, as it varies by model.
Is backstitching necessary on stretchy fabrics like knit or spandex?
Yes, even more so. Stretchy fabrics move a lot, and an unlocked seam will unravel quickly. Backstitch firmly at both ends, and consider using a ballpoint needle and stretch thread for extra security.
What happens if I backstitch too many times?
Backstitching five to seven times is safe and creates a strong lock. If you backstitch much more than that, you risk creating a thick, stiff knot that is hard to sew over later or that shows through thin fabric. Three to five stitches is the standard and is plenty.