Why Knit Hems Are Different From Woven Fabric
Knit fabric stretches and curls in ways woven fabric does not, so a regular sewn hem will pucker, pull, or break stitches when you wear the garment. The loops that make knit fabric flexible also mean a straight line of thread cuts across the grain instead of following it. A proper knit hem uses stitches that move with the fabric, or it folds the edge inward so the curl works in your favor instead of against it.
The two main routes are a blind hem (sewn by hand or machine, nearly invisible from the outside) and a fold-and-stitch hem (where you fold the edge twice and stitch it down, letting the natural curl of the knit hold the fold in place). Both work. The blind hem is more polished; the fold-and-stitch hem is faster and holds up longer because it has less strain on individual stitches.
Key Takeaways
- Knit fabric curls at the edges, so you must either use a stretchy stitch or fold the hem twice to contain the curl.
- A blind hem sewn by hand or machine is nearly invisible but requires care not to pull the thread too tight.
- A fold-and-stitch hem (folding the edge twice and stitching through all layers) is faster and more durable for knits.
- Always test your stitch and tension on a scrap of the same fabric before hemming the garment.
- Pressing a knit hem with steam can flatten it temporarily, but the fabric will spring back once worn.
Measuring and Marking Your Hem Line
Put on the garment or have someone wear it while you measure. Knit fabric drapes differently than woven, and the length can shift depending on how the piece is stretched. Mark the desired length with a fabric pen or tailor's chalk while the garment is on the body, standing in the shoes you plan to wear with it.
Measure up from the floor or from a table edge if the garment is laid flat. Mark a line all the way around, then take off the garment and lay it on a flat surface. Use a ruler or measuring tape to check that your marks are even. If the marks are uneven, re-mark them so the hem will be level when worn.
Decide how much fabric you need to fold up. For a fold-and-stitch hem, you need twice the finished hem width plus a quarter inch for the curl. If you want a half-inch finished hem, cut the fabric one and a quarter inches below your marked line. For a blind hem, cut one inch below the line.
The Fold-and-Stitch Method (Fastest for Most Knits)
Fold the bottom edge of the fabric up one half inch and press it lightly with your fingers or a cool iron. Do not use high heat on knit fabric—it can melt synthetic fibers and distort the stretch. Fold the edge up again another half inch so the raw edge is now hidden inside a double fold. The natural curl of the knit will help hold this fold in place.
Pin the fold every two to three inches, placing pins perpendicular to the fold so you can sew over them. Use a stretch stitch on your sewing machine if it has one—usually labeled with a zigzag or wavy line symbol. A stretch stitch moves side to side as it goes forward, so it flexes with the fabric instead of breaking when you wear the garment.
If your machine does not have a stretch stitch, use a narrow zigzag stitch (width 2 to 3, length 2 to 2.5). Sew about a quarter inch from the fold, keeping the stitches as straight as you can. Sew slowly and do not pull the fabric toward or away from the presser foot—let the machine feed it. Remove pins as you go.
Once you finish sewing all the way around, try on the garment. The hem should lie flat and move with you. If it pulls or puckers, you may have sewn too tight or used a stitch that does not stretch enough. If the hem is too long or too short, you can carefully cut away the extra fabric and re-fold and re-stitch.
The Blind Hem Method (Most Invisible)
A blind hem is sewn so the thread is hidden inside the fold, making it nearly invisible from the outside. Fold the hem up to your marked line and press lightly. Fold the top edge of the hem down about a quarter inch so a thin strip of fabric shows above the fold. This strip is where your stitches will go.
By hand: Thread a needle with thread that matches the fabric. Knot the end. Bring the needle up through the fold so the knot stays hidden inside. Take a tiny stitch (one or two threads) in the main garment fabric directly above the fold, then when ready take a stitch in the fold itself, going sideways about a quarter inch. Repeat all the way around. The stitches should be loose enough that the thread does not show when the hem is folded down. This takes longer than machine sewing but gives the most invisible result.
By machine: Use your sewing machine's blind hem stitch if it has one. Fold and press the hem as described above. Attach the blind hem foot (it comes with most machines). The foot has a guide that rides along the fold while the needle catches just a thread or two of the main fabric, then swings out to stitch into the fold. Sew slowly and test on a scrap first—the needle position takes practice to get right.
Fixing Common Mistakes
If your hem puckers or pulls, you sewed too tight. Knit fabric needs slack in the thread so it can stretch. Loosen your tension by one or two numbers on your machine, or if you sewed by hand, make sure your stitches are loose enough to move. You can also carefully cut out the stitches with a seam ripper and re-sew with looser tension.
If the hem curls up at the edges, the raw edge of the knit is showing and curling as knits do. Fold the hem again to hide the raw edge, or use a narrow zigzag stitch along the raw edge before you fold and stitch the hem. This is called finishing the edge and prevents the curl.
If the hem is uneven after sewing, measure again from the floor or a flat surface and mark a new line. You can cut away the old hem and re-fold and re-stitch. Knit fabric is forgiving—you can usually rip out stitches and start over without damaging the fabric.
Pressing and Finishing Your Hem
Use a cool iron or a pressing cloth between the iron and the fabric. Knit fabric can melt or lose its shape under high heat. Press from the inside of the garment, not the outside, so you do not flatten the texture. A light steam press can help set the fold, but the fabric will spring back once you wear it—that is normal and means the stretch is working.
If you used a fold-and-stitch hem, you may see a slight ridge where the fold is. This usually softens after the first wash and wear. If you used a blind hem, there should be almost no visible ridge from the outside.
Choosing Between Methods for Different Knit Types
Lightweight knits like jersey or interlock work well with either method. A fold-and-stitch hem is usually faster and holds up well. Heavier knits like sweater knit or rib benefit from a blind hem because the extra fabric in a double fold can look bulky. Stretchy knits like spandex blends need a very stretchy stitch—a narrow zigzag or a dedicated stretch stitch is essential, or the hem will break when you move.
If you are hemming a knit that has a lot of curl (like stockinette stitch in hand-knit garments), a fold-and-stitch hem works best because the curl is contained inside the fold. A blind hem on a very curly knit can look wavy from the outside.
Frequently Asked Questions
Can I use a regular straight stitch to hem knit fabric?
A straight stitch will eventually break because it does not stretch with the fabric. Use a stretch stitch, narrow zigzag, or a blind hem instead. If you only have a straight stitch available, sew very loosely and accept that the hem may not last through many washes.
What if my sewing machine does not have a stretch stitch?
A narrow zigzag stitch (width 2 to 3, length 2 to 2.5) works well on most machines and stretches enough for knit fabric. Test it on a scrap first to make sure the tension is right and the stitches are not too tight.
Should I use a serger to hem knit fabric?
A serger can finish the raw edge of a knit hem very neatly, but you still need to fold and stitch the hem itself. Some people serge the raw edge first, then fold and stitch with a regular machine. This prevents curling and looks professional.
How do I fix a hem that came out uneven?
Measure from the floor or a flat surface and mark a new line. Carefully cut away the old hem with scissors or a seam ripper, then fold and stitch again. Knit fabric is durable enough to rip out and re-do without damage.
Can I wash the garment right after hemming?
Wait at least a day so the stitches set. Washing when ready can loosen new stitches, especially if you sewed loosely (which you should for knits). After the first wash, the hem should be find.