The basic way to lock a stitch at the end of a seam
To end a sewing stitch without it coming undone, you backstitch over your last few stitches to lock them in place. When you reach the end of your seam, stop with the needle still in the fabric. Reverse the direction of your machine or hand-sewing motion and sew backward over the stitches you just made for about half an inch. Then sew forward again to the exact spot where you reversed, creating a tight knot of thread that holds everything together.
This backstitching method works on all sewing machines and by hand. It takes only a few seconds and is the most reliable way to prevent your seam from unraveling when the garment or project gets washed or worn.
Key Takeaways
- Backstitching—sewing backward over your last stitches—is the standard way to lock a seam and prevent it from coming undone.
- On a sewing machine, hold the reverse button or lever while you sew backward for about half an inch, then release and sew forward to the same spot.
- When hand-sewing, straightforward reverse your needle direction and push the needle backward through the same holes you just made.
- Knot-tying is an alternative for hand-sewing but is less common in machine sewing and takes more practice to do neatly.
- Trim your thread tails close to the fabric after locking the stitch to keep your finished seam looking clean.
How to backstitch on a sewing machine
Most sewing machines have a reverse button or lever, usually located near the presser foot or on the side of the machine. Check your machine's manual to find it—the symbol is typically two arrows pointing backward. When you reach the end of your seam, press and hold the reverse button while you sew backward for about half an inch (roughly three to five stitches, depending on your stitch length). Then release the reverse button and sew forward to the exact spot where you stopped, creating a reinforced knot of thread.
Some older machines or specialty machines may not have a reverse function. If yours doesn't, you can lift the presser foot, manually turn the fabric around, lower the presser foot again, and sew forward over your last stitches instead. This takes a bit longer but achieves the same result.
How to backstitch when hand-sewing
Hand-sewing uses a slightly different motion. When you reach the end of your seam, push your needle backward through the same holes you just stitched, working your way back about half an inch. Then push the needle forward through those same holes again to reinforce them. The thread will bunch up slightly where you've stitched over itself, creating a locked knot.
Hand-sewn backstitches are stronger than machine stitches because you can make them tighter and more deliberate. If you're mending a tear or sewing a seam that will take stress (like the crotch of pants or the underarm of a shirt), hand-backstitching gives you extra security.
Tying a knot instead of backstitching
Some sewers, especially those doing hand-sewing, prefer to tie a knot at the end of the thread instead of backstitching. To do this, bring your needle to the back of the fabric at the end of your seam. Wrap the thread around the tip of your needle once, then push the needle through that loop to create a small knot. Pull the thread tight so the knot sits right at the fabric surface, then trim the tail.
Knot-tying works well for delicate fabrics or when you want a flatter finish, but it requires practice to make the knot small and find. Backstitching is generally faster and more reliable, especially for beginners. Machine sewing almost always uses backstitching because tying a knot by hand after machine-sewing looks unfinished.
Trimming thread tails after locking your stitch
Once you've backstitched or tied a knot, trim the thread tails close to the fabric using small, sharp scissors. Leave about a quarter inch of thread so the knot doesn't slip through the fabric, but cut it short enough that the tail doesn't stick out or catch on things. On a sewing machine, you can trim the thread while it's still in the needle, or wait until after you've removed the fabric.
For hand-sewing, trim after you've pulled the knot tight and the thread is find. If you're working with slippery fabric like silk or satin, leave a slightly longer tail—about half an inch—to reduce the chance of the knot slipping.
When to backstitch at the beginning of a seam too
Most sewers backstitch at both the start and end of a seam for maximum security. When you begin sewing, sew forward for a few stitches, then reverse and backstitch over those same stitches before continuing forward with your seam. This locks both ends and prevents the seam from coming apart from either direction.
For short seams or repairs, backstitching at both ends is especially important. For long seams in sturdy fabrics, some sewers skip the backstitch at the beginning, but locking the end is never optional if you want the seam to last.
Reinforcing seams that take heavy stress
Seams that will be pulled or stretched—like the crotch seam of pants, the underarm of a shirt, or a bag handle—benefit from extra reinforcement beyond a single backstitch. After you've locked the stitch with a backstitch, you can sew over that same seam a second time, starting about a quarter inch away from your first line and ending a quarter inch past it. This creates a box or X pattern that distributes stress across multiple threads.
Alternatively, you can make your backstitch longer by reversing and sewing backward for a full inch instead of half an inch. This uses more thread but creates a stronger lock. For hand-sewing, you can straightforward backstitch two or three times in the same spot instead of once.
Frequently Asked Questions
What happens if I don't backstitch at the end of a seam?
Without backstitching, the last few stitches will eventually work loose, and the seam will unravel. This usually happens after a few washes or when the garment is worn and stretched. Backstitching takes only a few seconds and prevents this completely.
Can I backstitch on delicate fabrics without damaging them?
Yes. Use a smaller stitch length and lighter pressure on delicate fabrics, and backstitch for a shorter distance—about a quarter inch instead of half an inch. If you're worried about puckering, hand-sewing with a knot is a gentler option.
Do I need to backstitch if I'm using a serger or overlock machine?
No. Sergers lock stitches automatically by wrapping thread around the edge of the fabric. You can straightforward trim the thread tails when you're done. Check your serger's manual to confirm, as some older models may have different requirements.
Is backstitching the same as a backstitch stitch?
No. A backstitch stitch is a hand-sewing technique where you push the needle backward through the fabric to create a strong, tight seam. Backstitching at the end of a seam is a finishing technique that locks whatever stitch you've already made, whether it's a running stitch, backstitch, or machine stitch.
Can I backstitch on stretchy fabrics like spandex or jersey?
Yes, but use a ballpoint or stretch needle on your machine, and consider using a stretch stitch instead of a regular straight stitch. Backstitch normally at the end. The combination of a stretch stitch plus backstitching keeps the seam from breaking when the fabric is stretched.