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Tutorial: Sewing hems on knits with a twin needle


Today, we’re bringing you another excerpt from the forthcoming book, The Colette Guide to Sewing Knits. We’re learning how to sew a hem using your standard sewing machine and a twin needle.

In the world of ready-to-wear, a coverstitch machine is usually used for creating neat hems with stretch. But you can still create that same look and functionality without a coverstitch, and even without a serger!

All you need is a twin needle, a type of forked sewing machine needle that lets you sew two rows of stitching at once. Twin needles come in multiple widths. The wide width (1/4″) will closely mimic the look of a coverstitch.


  1. To start, finish the raw edge of your hem. You can use a serger to overlock the edge, or use your sewing machine’s mock overlock stitch or a zigzag stitch to finish. While this step is not 100% necessary, it helps to create a cleaner and more durable edge.


  1. Turn the finished hem under and press into place. If possible, stabilize your hem with a product such as Wonder Tape (see note below). Lower the bobbin tension to prevent the rows of stitches from forming a raised channel.


  1. Insert the twin needle and follow your sewing machine’s manual for threading it with two spools of thread. Stitch the hem in place with a straight stitch, catching and securing the raw edge beneath, just like a coverstitch. See The Colette Guide to Sewing Knits, pp.82-83 for tips on maintaining an even hem. The underside of the stitch will have a zigzag, allowing the stitches to stretch.

Stabilizing hems


Sometimes hems on knits can get a little wavy when they’re sewn using the twin needle technique. This is usually because the fabric is being stretched a bit as it’s sewn. To help get a crisp hem, try using a wash-away stabilizing tape, such as Wonder Tape. Wonder Tape is adhesive on both sides, so it even holds your hem in place while you sew!

Apply the tape to the wrong side of the fabric near the raw edge. Remove the backing, turn the hem up, and use the tape to adhere it in place. The tape will keep your hem in place while you sew, minimizing stretch, but will wash away later. Another option is a fusible interfacing tape, such as Stitch Witchery.

Have you ever sewn a knit hem this way? What problems or challenges did you have? Any additional tips to share?

Sarai Mitnick


Sarai started Colette back in 2009. She believes the primary role of a business should be to help people. She loves good books, sewing with wool, her charming cats, working in her garden, and eating salsa.



April 9, 2014 #

I’m sewing my first knit garment right now and I never used my twin needle before so your tip couldn’t come at a better time. As Wonder Tape is available here in Germany, so I will give it a try. I’m really looking forward to your book and the new patterns.


April 9, 2014 #

I always read to sew with knits you must use a ball point needle. However when it comes to twin needle that is not mention; moreover, it is hard to find a ball point twin needle or is non existant! What is your recomendation. I have also the same question for serger needles; do you need to change the needle to a ballpoint?


April 9, 2014 #

There are ballpoint twin needles -the package says “stretch”. I’m not sure where you are located, but I use the Schmetz brand. I have been able to find them at Jo-Ann fabrics and also ordered them online for a reasonable price.


April 9, 2014 #

Oh Yes, does anyone know if there is such a thing as ballpoint serger needles?


April 9, 2014 #

I’ve started using ELX needles which I believe are ballpoint for serger. They’ve made a big difference in reducing the number of skipped stitches I’m getting!


April 9, 2014 #

I used a ballpoint twin needle at first, and I had so many skipped stitches no matter what other tricks I tried, so I switched to a universal twin and suddenly no skipped stitches (on my old machine – I still get a few on my new one). The universal was also a better quality needle (Schmetz) vs the ballpoint (Xlasse), so that may have also made a difference, but my local fabric store doesn’t have a lot of options, so they didn’t have a twin ballpoint or stretch Schmetz to try.

Also, there is a difference between ballpoint and stretch. A stretch needle has a more rounded point than a ballpoint, and an anti-cling coating to help prevent skipped stitches in knits and elastic (this is from my Bernina Workbook 1 pg.5 for getting to know your machine).


April 9, 2014 #

This is my favorite way of sewing a knit hem! I have been sewing so long that I had forgotten that most people have never heard of a twin needle. I was surprised to find that my mom, who taught me to sew, didn’t know what it was or when to use it. After that, I wrote a 2 part post about when to use twin needles, how to thread them, etc. I had taken for granted the tips I have picked up along the way!


April 9, 2014 #

I’ve always known about twin needles, yet for some reason the thought never occurred to me to use them on knits. This is neat!


April 9, 2014 #

This is a great tip. I always use a twin needle for hemming knits. I’ve have always used Stitch Witchery and it works great–really, this combo made sewing knits a real pleasure. I can’t wait to try Wonder Tape; it sounds even better than Stitch Witchery!

Kathy Sews

April 9, 2014 #

Twin needle stitching is fantastic when you don’t have the $$ for a coverstitch! I use a bias tape, fusible on one side, from Pellon called Easy Knit Tape when I want my hem to be stabilized. It’s marketed to quilters as a batting and seam tape… but it’s meant to also be a stabilizer for straight and curved edges. It works great, it’s dirt cheap (about$5 for 10 yds) and can be found in big box sewing stores… it’s manufactured in a wider size (maybe an inch? I forget off the top of my head), so I cut it down the middle as I use it, then it’s really 20 yards of material.


April 9, 2014 #

What great timing! I sewed my first knit twin needle hem yesterday. I bought quite a narrow twin needle, not knowing the difference, but having looked at a few RTW items, I can see that their double rows of stitching are much further apart, like yours is here.

Yesterday I also used Stitch Witchery for the first time for a neckline. It gave a nice clean edge, but I found it a little stiff once fused on. Is Wonder Tape better for this? What is the difference between the two?

Really looking forward to his book coming out. Thanks for the excerpts!


April 9, 2014 #

Wonder Tape is sticky on both sides and washes away when the garment is laundered. Since it washes out, it’s not stiff like Stitch Witchery or Steam-a-Seam. Wonder Tape is awesome!! At my Jo-Ann’s it’s with the quilting notions.


April 9, 2014 #

Thanks for the tip about the wonder tape. I will give this a go. Sometimes my twin needle does that chanelling thing.

Jennifer Lachman

April 9, 2014 #

I’ve tried a twin needle on my machine, but I don’t have a spool holder for the second thread. I finally figured out that a travel coffee mug works just as well as long as I sew slowly. If I go to fast it tends to get tangled.


April 9, 2014 #

Try using a wound bobbin for a quick fix for the second thread. If your machine has another spool holder, just pop it in there! I’m also a huge fan of these:

This one is a tad expensive, but I have a plastic one I picked up at Fabric Depot in Portland for around $10. Or if you have a lot of thread cones, this is the best for getting the correct tension in a single needle machine.


April 10, 2014 #

Hey, I just posted a picture on my bog yesterday of my spool holder substitute! I found an example online of someone who tapes a piece of dowel onto their machine. I tried it with a paint brush because it was handy. Sounds a bit crazy but it works really well as as interim (or long term!) solution. Take a look at my latest post to see what I’m talking about :)

Jessica H

April 9, 2014 #

Another thing I’d HIGHLY RECOMMEND is using a walking foot when you are hemming knits with a twin needle. When I use my walking foot, I don’t usually have to stabilize the seam with tape, because the walking foot prevents the fabric from stretching as much. It also ensures an even feed between the top and bottom layers of fabric.


April 10, 2014 #

I was going to say the same thing. I just learned how to attach/use the walking foot that came with my machine, and it makes a WORLD of difference!

Lady ID

April 9, 2014 #

So far the hems of my knit projects have all been completed using a stretch twin needle. I haven’t needed to stabilise the hem because I lightly push my fabric forward as I sew to avoid stretching it out. This technique hasn’t worked as well on armholes and necklines but it’s getting there. I plan to get a walking needle as Jessica H. suggested.


April 9, 2014 #

I’m not a fan of twin needle stitching for a number of reasons – the needle is prone to breakage, and those needles are expensive! There’s also that tunneling issue (which you addressed) BUT loosening your bobbin case is tricky and hard to return its original tension. Better option is to buy a bobbin case strictly for twin needle stitching, adjust the tension for that and use it strictly for twin needle stitching. A better option is the Coverstitch machine, which uses two needles and there’s no tunneling at all. Of course, not everyone will have a Coverstitch machine, but this kind of finish is going to look at more RTW than the twin needle stitching on a sewing machine.


April 9, 2014 #

I learned to do this years ago before I owned a cover stitch machine. It worked beautifully every time! If you’re shortwaisted and full in the hips, this is a valuable skill to have. . .


April 9, 2014 #



April 9, 2014 #

I’ve got issues with tunneling – and I can’t adjust my bobbin tension – but I’m hoping that stabilizing the hem would help. I love Wonder Tape but mostly use it with zippers (instead of basting). I’ll have to try it on a knit hem next time.

The other issue I get is that the hems flip up. I don’t think it’s just contained to twin-needle-stitched hems; maybe it has more to do with the weight or type of knit being used. I’ve noticed it with jersey, which likes to roll towards the right side anyways, and think this is just because that’s what jersey does. Would a twin needle effect it in any way?


April 13, 2014 #

If you’re sure you can’t adjust your bobbin tension (mine is just a nondescript screw), just make sure when you wind the thread on the bobbin you do it slowly – if you do it faster, the bobbin thread gets wound on tighter and I think it makes it more likely to tunnel.

Sarahlee Kittons

April 9, 2014 #

Thanks for posting, enjoy and have been doing this exact technique for a boutique where I do alterations. Experimenting on the scraps I remove many times over. These super fine or should I say ‘thin’ knits (and won’t divulge brand names here) are a real challenge as the channel the twin needle makes is almost impossible to avoid unless you use a stabilizer. With some types of stabilizers you give up the stretch, you were trying to create with the similar look of the coverstitch.
I’ve found also, that turning down the pressure on the foot or using a roller foot helps with the puckering. Wooly nylon is my best bobbin thread friend when sewing knits with the double needle or other stitches – just to give it that extra bit of stretch. Just make sure you lower tension on the bobbin when using wooly nylon. I do this on stretch jeans also – especially the skinny ones.


April 9, 2014 #

I would try this but I managed to bend my twin needle on the first try and now have to get a new one. :P


April 9, 2014 #

Great tip with the wonder tape! I bought some fusible webbing and it’s also great for use on wovens when sewing tricky things like sleeve plackets. Keeps everything nice and stable as you stitch for really precise and professional results. Looking forward to the book!

Luna Badoona

April 9, 2014 #

Thanks so much for this tip! I’ve recently started sewing with knits a lot – I tried to use a twin needle once but it was a disaster! haha! I think I’ll give it another crack after reading this :)


April 10, 2014 #

I’m learning so much from these posts already–including why the knit batwing t-shirt I just made with my new twin needle for my daughter has those raised seams! Can’t wait to get the book. :)

Jet Set Sewing

April 10, 2014 #

I’m really looking forward to your book. I learned to sew knits on a straight stitch machine in the 70s (it can be done if you “stretch and sew”…) but now that I’m working with wool jersey on some vintage Claire McCardell projects, I’m looking forward to upping my game.


April 13, 2014 #

I actually don’t overlock the hem first; instead I use the zig-zag from the bobbin thread to finish it off like a coverstitch. You just have to make sure you measure the hem before pressing so you can be sure you’ll catch the free edge in the stitching (same as with a coverstitch machine). If you need to you can go and trim the free edge if you need to.

I think it might be worthwhile for you to have a picture of what the underside looks like when using a twin-needle, for beginners – I wasn’t sure if I had done something wrong when I was first presented with the zigzag!

shirley cree

April 15, 2014 #

the other ‘trick’ i discovered thru this site…………using stretch thread in the bobbin…..(haven’t figured out how to use it as top thread without making sporadic thread nests on the underside….. )…. with a twin needle…. makes sewing knit hems a dream…….

Laura Reed

May 22, 2014 #

This has been really helpful for me! I’ve used it on two dresses already and then ordered your book! And the Monetta pattern! Thank you so much for sharing your expertise.


May 25, 2014 #

Fantastic tips. I bought the walking foot. It is fantastic. I will buy the strech needles to see the difference.