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Sewing Knits on a Regular Machine: Needles, Stitches and the Fix for Skipped Stitches
You do not need a serger to sew knits. You need a ball point or stretch needle, a stitch that can stretch with the fabric, and usually a small reduction in presser foot pressure. That combination handles t-shirts, leggings, sweatshirts and most jersey garments on an ordinary sewing machine.
What follows is why each of those three things matters, because knits fail in specific ways and each failure has a specific cause. Once you can read the symptom, you stop guessing.
Why knits break the rules woven fabric follows
A woven fabric is a grid of threads crossing at right angles. Put a needle through it and you pass between threads; the fabric holds still because the grid has no give along the grain.
A knit is made of interlocking loops, and that construction creates two problems at once.
The fabric moves with the needle. Because a knit stretches, the fabric flexes downward as the needle descends instead of resisting it. On the upstroke, the needle needs to form a small loop of thread for the hook to catch — that loop formation is what makes a stitch.
If the fabric is still traveling with the needle, the loop forms late or does not form cleanly, the hook passes by, and you get a skipped stitch. This is why skipped stitches on knits come in runs rather than singly: once the fabric starts moving with the needle it keeps doing it.
A sharp point cuts loops. A universal needle has a slightly rounded point, but a genuinely sharp needle will sever a loop rather than pushing between fibers. A severed loop in a knit does not stay put the way a cut thread in a woven does — it unravels. Those small holes that appear along a seam a week after you sew it are cut loops working themselves open.
Both problems are solved at the needle.
The needle is the fix
| Needle | Use it for | What it does differently |
|---|---|---|
| Ball point / jersey | Jersey, interlock, cotton knits, sweatshirt fleece | Rounded point pushes between loops instead of piercing them |
| Stretch | Lycra and spandex blends, swimwear, activewear, elastic knitwear | Ball point plus a modified eye and scarf that help the hook catch the loop — this is the skipped-stitch needle |
| Universal | Stable knits at a pinch | A compromise point. Works sometimes; is not the answer when something goes wrong |
| Twin needle | Hems | Two parallel rows on top, a zigzag of bobbin thread underneath that provides the stretch |
The distinction people miss is between ball point and stretch. Both have rounded points, so both protect the loops — but only the stretch needle addresses the timing problem. If you are getting holes, a ball point fixes it. If you are getting skipped stitches on a very elastic fabric, a ball point often will not, and a stretch needle usually will.
Size follows fabric weight in the normal way: 70/10 for fine jersey, 80/12 for standard t-shirt weight, 90/14 for sweatshirt fleece and heavier interlock. Schmetz 70/10, 80/12 and 90/14 ball points cover the range, or the assorted pack if you are not sure yet. If it is skipped stitches rather than holes you are fighting, stretch needles are the ones to reach for — Schmetz 75/11 for lightweight knits and 90/14 for heavier ones.
Full sizing logic is in our needle sizes and types guide.
One more thing on needles: change them more often than you think. Schmetz's own guidance is roughly eight hours of sewing, or the start of each project. A dulled ball point behaves like a sharp needle, which brings the holes back.
Three stitches that stand in for an overlock
A straight stitch has no give. Sew a knit seam with one, pull the seam, and the thread — which cannot stretch — snaps. That is the popped seam in a home-made t-shirt, and it is a stitch choice problem rather than a thread quality problem.
| Stitch | Starting settings | Best for |
|---|---|---|
| Narrow zigzag | Width 0.5–1.0mm, length 2.5mm | General seams. Looks almost like a straight stitch but has give |
| Triple stretch ("lightning bolt") | As your machine sets it | Seams that take strain — crotch seams, shoulder seams, activewear |
| Built-in overlock stitch | As your machine sets it, with the overcast foot if you have one | Sewing and finishing the edge in one pass |
| Twin needle | Straight stitch, top tension slightly reduced | Hems and cuffs |
The narrow zigzag is the workhorse and it is underrated. At 0.5mm width the seam reads as straight to the eye but has enough lateral movement in the thread to survive being stretched. Start there before reaching for anything more exotic.
The triple stretch stitch is stronger but sews forward-backward-forward, which means it is slow and nearly impossible to unpick cleanly. Use it where strength matters and save yourself the grief everywhere else. Our stitches explained guide covers what else is on your stitch dial.
The settings people forget to change
- Presser foot pressure. If your machine has an adjustable pressure dial, reduce it. High pressure stretches a knit as it feeds, which is what produces a seam that comes out longer and wavier than the pieces you cut. This is the single most effective setting change on the list, and most people never touch that dial.
- A walking foot. Same purpose from the other direction — it moves top and bottom layers together instead of letting the feed dogs drag the underside along. See walking foot vs built-in dual feed for which your machine already has.
- Stitch length. Slightly longer, around 3mm, on stretchy fabric. A dense line of short stitches perforates a knit and creates a weak line right where the seam is.
- Thread. Polyester, not cotton. Polyester has a little natural give and cotton has effectively none. See polyester vs cotton thread.
- Stabilizer at the shoulders. A strip of clear elastic or fusible stay tape in shoulder seams stops them growing under the weight of the garment. Small step, large difference over the life of a t-shirt.
Symptom, cause, fix
| What you see | Most likely cause | Try first |
|---|---|---|
| Skipped stitches, in runs | Needle cannot form a clean loop in flexing fabric | Stretch needle; then slow down; then rethread |
| Small holes appearing along the seam | Sharp or blunted point cutting loops | Fresh ball point needle |
| Seam pops when stretched | Straight stitch with no give | Narrow zigzag or triple stretch |
| Seam comes out wavy and longer than the pieces | Fabric stretched while feeding | Reduce presser foot pressure; walking foot; stop pulling the fabric |
| Fabric gets pushed into the needle plate at the start | Lightweight knit and a wide needle hole | Straight stitch plate if you have one; start on a scrap leader |
| Tunneling between twin-needle rows | Top tension too high | Reduce top tension; wooly nylon in the bobbin |
| Puckered seam | Tension, or too short a stitch | See our puckering guide |
If skipped stitches persist after a new stretch needle, the problem may not be the fabric at all — our skipped stitches guide covers timing and hook issues, and rethreading top and bobbin from scratch is always worth doing first. The threading tutorial walks it if your machine is unfamiliar.
Hemming, which is the part that gives people the most trouble
A knit hem has to stretch to go over a head, a shoulder or a hip, and then recover. The professional answer is a coverstitch. The domestic answer is a twin needle — a twin stretch needle if you can get one, but a standard twin works: two straight rows on the outside, and underneath, the bobbin thread zigzags between them, which is where the stretch comes from.
Two adjustments make twin-needle hems behave. Reduce your top tension a little — the ridge that appears between the two rows, called tunneling, is almost always excess top tension. And consider wooly nylon in the bobbin, which is textured and stretches far more than ordinary thread, giving the hem noticeably more recovery.
Press the hem allowance up and use a fusible hem tape to hold it before sewing. Pins distort a knit hem while you sew it, and you will see every distortion in the finished row.
When it is worth buying the machine instead
Everything above works. It is also slower than a serger, and if you sew knits regularly the arithmetic changes. A serger trims, sews and overcasts in one pass, feeds with differential feed that prevents waviness at the source, and produces a seam that is both stretchier and more durable than anything a straight-stitch machine can make.
The honest threshold: if knit garments are an occasional project, your sewing machine is fine and the needle change is the entire upgrade. If you are making several knit garments a month, a serger pays for itself in time before it does in quality. Our sewing machine vs serger comparison lays out the difference, what is a serger covers the basics, and coverstitch vs serger covers the hemming machine specifically.
Quick answers
Can I just use a universal needle?
On a stable, low-stretch knit, often yes. The moment anything goes wrong — holes, skipped stitches, runs — the universal needle is the first thing to change, not the last.
Do I need to prewash knit fabric?
Yes, and more urgently than with quilting cotton. Knits shrink more, and cotton jersey in particular can shrink noticeably in the first wash. Wash and dry the way you intend to treat the finished garment.
Why does my seam ripple only on long seams?
Because the stretching is cumulative. A 4" seam hides it; a 30" side seam shows every bit. Reduce presser foot pressure and let the machine feed the fabric rather than helping it along.
What about very stretchy swimwear fabric?
Stretch needle, polyester thread, narrow zigzag, and clear elastic in any seam that has to hold shape. Swimwear is the fabric that punishes every shortcut on this list at once.
Start with the needle — sewing machine needles or the full needle range — and pick up polyester thread from sewing thread. If a serger is on the cards, sergers and overlock machines and our 2026 serger comparison are the next stop.