What a top stitch is and why you use it
A top stitch is a line of stitching sewn on the outside of fabric, usually close to a seam or edge. It serves two purposes: it holds layers together permanently and creates a visible line that looks intentional—either as a design detail or as a reinforcement. You'll see top stitching on jeans (especially around pockets and hems), on the edges of collars, and on seams that take heavy wear.
The top stitch is stronger than a regular seam because the thread runs parallel to the seam line rather than perpendicular to it, and because it's visible, you can see when ready if it's straight and even. For repairs, a top stitch is the right choice when you're mending a tear in a visible spot, reinforcing a seam that's starting to fail, or hemming something where you want the stitching to show.
Key Takeaways
- A top stitch is sewn on the outside of the fabric, parallel to a seam or edge, and is both functional and decorative.
- Thread weight matters: use thread that matches your fabric weight, and consider using topstitching thread (thicker than regular thread) for visible seams on heavy fabrics like denim.
- The distance from the edge or seam—usually one-eighth to one-quarter inch—must stay consistent the entire length for a professional look.
- Sew slowly and use a longer stitch length (3.0 to 3.5 mm) than you would for a regular seam to prevent puckering and keep the line straight.
- A walking foot or even-feed foot helps fabric move evenly under the needle, especially on knits or when sewing through multiple layers.
Choosing the right thread and needle
Regular sewing thread works for light fabrics, but for a top stitch that will be visible and take stress, match the thread weight to your fabric. On denim, canvas, or heavy cotton, use topstitching thread, which is thicker (usually 30 weight instead of 50 weight) and creates a bolder line. Topstitching thread also resists breaking under tension.
The needle size matters too. A size 80/12 works for light fabrics; move to 90/14 for medium weight, and 100/16 or 110/18 for heavy fabrics or topstitching thread. If your thread is thicker than regular thread, you may need to increase the needle size so the thread passes through the eye without fraying. Check your machine's manual—some machines have a special topstitching needle with a larger eye and deeper groove to accommodate thick thread.
Wind your bobbin with regular thread (the same weight as your needle thread, or lighter), and thread the needle carefully. If you're using topstitching thread, some machines require you to loosen the top tension slightly so the thicker thread doesn't bunch or break.
Preparing the fabric and marking your line
Press the seam or edge you're about to top stitch so it lies flat. If you're reinforcing an existing seam, press it to one side first. If you're hemming, fold and press the hem to the finished length before you stitch.
Mark the distance from the edge or seam where your top stitch will run. Most top stitching sits one-eighth inch to one-quarter inch away from the seam line. Use a ruler and a fabric pencil, chalk, or a washable marker to draw a light line, or use painter's tape as a guide—place the edge of the tape at your marked distance, and sew along the tape edge. Remove the tape when ready after sewing; leaving it on can leave adhesive residue.
For a seam that's already sewn, you can also use the presser foot width as a guide. If your foot is one-quarter inch wide, align the edge of the foot with the seam and sew; the needle will land one-quarter inch away. Test this on scrap fabric first to confirm the distance.
Setting up your machine and sewing slowly
Set your stitch length to 3.0 to 3.5 mm—longer than a regular seam (which is usually 2.0 to 2.5 mm). A longer stitch is less likely to pucker the fabric and is easier to keep straight because you have more time to adjust before the needle moves again. If you're using topstitching thread, a longer stitch also reduces stress on the thread.
If your machine has a walking foot (also called an even-feed foot), install it now. A walking foot moves the top layer of fabric forward at the same rate as the feed dogs move the bottom layer, which prevents puckering and keeps layers from shifting. This is especially helpful on knits, stretchy fabrics, or when sewing through more than two layers.
Lower the presser foot, take one stitch by hand (turn the wheel toward you), and check that the needle is landing where you want it. Sew slowly—use a speed that lets you steer comfortably and stop if something goes wrong. Sew in a straight line, keeping your eye on the marked line or the tape edge, not on the needle. Most machines have a needle-down setting; use it so the needle stays in the fabric when you stop, which helps you pivot or adjust without the fabric shifting.
Keeping the stitch line straight
The most common mistake is drifting away from the marked line. To stay straight, focus on the line ahead of the needle, not on the needle itself. Your hands should guide the fabric gently—do not pull or push. Let the feed dogs move the fabric; your job is to steer.
If you're sewing along a seam, align the edge of your presser foot with the seam line and keep that alignment constant. If you're using a marked line, keep the needle on the line. If you drift, stop with the needle down, lift the presser foot, and adjust the fabric slightly. Lower the foot and continue.
For long seams, take a break every few inches, lift the presser foot (needle stays down), and check that you're still on track. Correcting a small drift early is much easier than ripping out a whole seam.
Finishing and securing the thread
When you reach the end of the seam, sew a few stitches past the edge, then backstitch (reverse) over those last few stitches to lock the thread. Backstitch for about one-quarter inch, then sew forward again to the end. This creates a knot that won't unravel.
Raise the presser foot and pull the fabric away from the machine. Leave a tail of thread about four inches long on both the top and bobbin. Trim the tails close to the fabric with scissors. If the thread ends are frayed or loose, you can tie them together on the back and trim, or explore a tiny drop of clear fabric glue to seal the knot—but this is optional for a top stitch, which is already locked by the backstitch.
Press the finished top stitch with an iron on low heat to set it and remove any puckering. The stitch should lie flat and straight.
Fixing common problems
Puckering or gathering: This usually means the stitch length is too short, the tension is too tight, or you're pulling the fabric. Increase stitch length to 3.5 mm, loosen the top tension by half a number, and let the feed dogs do the work. If you're sewing through heavy layers, use a walking foot.
Broken thread: If topstitching thread keeps breaking, the needle eye may be too small. Move up to a 100/16 or 110/18 needle. Also check that the thread is wound smoothly on the bobbin and that the presser foot is raised when you thread the needle (raising it opens the tension discs).
Skipped stitches: This usually means the needle is bent or the needle size doesn't match the thread. Replace the needle and confirm the size is correct for your thread weight. Also check that the needle is inserted all the way into the needle clamp.
Wobbly or crooked line: Sew more slowly and focus on the line ahead, not the needle. Use a marked line or tape as a guide. If the fabric is slippery, use a walking foot or place a piece of tissue paper under the fabric to stabilize it (tear it away after sewing).
Frequently Asked Questions
Can I top stitch by hand?
Yes. Use a backstitch or running backstitch with thread that matches your fabric weight. Make stitches about one-eighth inch long and keep them evenly spaced. Hand stitching takes longer but gives you complete control and works well for small repairs or heirloom fabrics.
What's the difference between top stitching and edge stitching?
Edge stitching is a top stitch sewn very close to the edge—usually one-eighth inch or less—and is often used on collars, cuffs, and facings. Top stitching is the broader term for any visible stitch on the outside of fabric, and can be further from the edge. The technique is the same; only the distance changes.
Do I have to use topstitching thread?
No. Regular thread works fine on light and medium fabrics. Topstitching thread is thicker and more visible, which is why it's popular on denim and canvas, but it's not required. Use what you have if the fabric is light enough; the stitch will still be strong.
Why does my top stitch look wavy?
Waviness usually comes from sewing too fast, pulling the fabric, or using a stitch length that's too short. Slow down, let the machine feed the fabric, and increase stitch length to 3.0 to 3.5 mm. If the fabric is stretchy, use a walking foot to keep layers moving together.
Can I top stitch a curved seam?
Yes, but it's harder to keep the line straight. Mark the curve lightly with chalk or a pencil, sew very slowly, and use a shorter stitch length (2.5 to 3.0 mm) so you can adjust more often. Practice on scrap fabric first. A walking foot helps on curves too.