Twin needle tips

I sew a lot of knits. When I started sewing clothes, it didn’t really occur to me that knits were something you even could sew – RTW knit items seemed so professionally finished and out of reach of the home sewist. Ha, how wrong I was! Once I started sewing knits (by the way, I started with drapey cardigans like Simplicity 2603 – no hems or neckbands!) I kind of never looked back. I do still sew wovens, of course, and occasionally it’s so nice to work with something that behaves itself all the time (pressing, what a concept), but I like how forgiving knits are in terms of fit (and also bad cutting – if the edges don’t line up exactly, just stretch it!). But to master knits, and make them look more like RTW knit garments, I had to figure out hemming. Someday, when I have several extra hundred dollars and an actual sewing room rather than just my kitchen table, I may consider getting a coverstitch machine, but since neither of those things seem likely in the near future, for now I have become an pro at the twin needle. I thought I’d share a couple things I’ve discovered about twin needle hemming, since actually there’s not a whole ton of detailed information out there, especially about securing the stitching. I won’t do the basics, since a google search will turn up a bunch of videos and things to get you started (here’s a nice overview), but I’ll just give some random tips and tricks I’ve picked up.

These are the needles I use (I stock up at Jo Ann during the half-off notions sales – one starts today!). For a while I went out of my way to get the stretch twin needles (only available at one local sewing machine store, and expensive), but I’ve actually found the regular ones to work just fine on all but the most slinky stretchy poly jerseys.

If there’s one thing I’ve noticed about sewing with twin needles, it’s that every sewing machine does it differently. Sure, you have to have two spools (I keep an old bobbin around to wind as my second spool), and thread both threads through the machine to the needle, but my old machine (a cheapo Sears-branded Singer) preferred that both threads go through the machine together, while my new machine (Bernina 1230) is very, very picky about threading. It is vital that I start with the right-hand spool, have the thread coming off the front of the spool, make sure it gets on the right side of the tension disc, and through the little thread catch above the needle, while the left spool must have the thread coming off the back, go on the other side of the tension disc, and not into the thread catch at all (why is that important? no idea, but repeated thread nests tell me it is). Here’s a look at what I mean:

I also always have to lower the tension to get a good stitch. I’ve found, with this machine at least, that the thinner the fabric, the lower the tension. For really thin knits I’ve had it all the way down to .5! Usually around 2 is about right, though. Test swatches are your friend!

At first I tried to secure the start and end of the stitching by backstitching, but several pulled-out hems indicated I needed another method. (Also, the Bernina gets all tangled up if I backtack with a twin needle.) Now I simply tie the thread ends to each other. For a regular hem (one that starts and ends at the same point), I stop sewing as close to my start point as possible (without overlapping), then I tie the two top threads to their counterparts, and on the reverse side, I tie one bobbin thread end to the other. I’ve found this to be much more secure. Here’s a picture showing the top threads tied off (I always start and end at a seam), as well as the reverse side of the stitching (yes, I used white bobbin thread so I wouldn’t have to wind a second bobbin. Let’s pretend I did it for demonstration purposes.):

But what to do about hems on sleeves, for example, that don’t start and end at the same place? Here’s my cunning (I think so, anyway, maybe everyone does this?) method for tying off the thread ends: I thread both of the top threads through a needle, stick the needle in between the two lines of stitching, and pull the threads to the back. Then I tie the bobbin thread to the two top threads.


Easy, clean, and secure! This example is from my Vogue 1250, but I’ve also used it on Vogue 8728, Vogue 1224, and Simplicity 3503 (that’s a lot of dresses with cut-on cap sleeves – do I have a thing?)

Finally, as great as the twin needle is, it’s still not as durable as a professional coverstitch, and I do still get popped hems occasionally when the bobbin thread just breaks somewhere in the middle of the hem. Rather than rip out and re-do the whole hem when that happens, though, I’ve discovered that I can carefully pull a short tail of bobbin thread out on both sides of the break, then pull out the top threads from that section (leaving them long too), and just re-sew the short section of hem. Then I tie off all the new threads to the old ones. Patched!

I really like hemming knits with a twin needle, and I do encourage you to try it if you never have. Don’t get discouraged if your machine seems to hate it – just keep re-threading and trying again until you find the right threading method and tension for your machine. Twin needle hemming has become my preferred knit edge finish method for all patterns, but I’m still amazed that no pattern instructions recommend it or even mention it! It can be tricky, but I think it’s totally worth it. What about you?

  1. Thank you for posting this! I just bought my first twin needle… and promptly shelved it after my first attempt at using it. Your hints on tension are exactly what I need: I was trying to hem a jersey and I couldn’t figure out why everything was bunching up so badly. I’ll take another shot at it today!

  2. I have been wanting to try this. You’ve made it sound so unthreatening!

  3. Pam F. said:

    How do you keep the fabric from tunneling between the 2 rows of stitches?

    • aleah said:

      Ah, the infamous tunneling! It’s all in the tension adjustment. I do a bunch of test swatches and lower the tension until it lays flat(ish), but the stitching isn’t too loose on the back. There’s still more tunneling than, say, a coverstitch, but it’s not too bad. It’s worse on really light fabrics. If anyone has any other advice on making it lay flatter, let me know!

  4. Thanks Leah, I wonder if it’s possible to fit twin needles to most machines? I might actually be tempted with sewing more knits!

    • aleah said:

      You can use a twin needle on any machine that has zig-zag capability (because the bobbin is making a zig-zag even if the top needles aren’t), so pretty much any modernish machine. My mom’s 1930s table-attached Singer can’t use one, for instance, but probably any portable machine from the 70s to now could. (When did the zig-zag stitch become a thing? Anyone know?)

      • grtescp said:

        I use my my 1960s Bernina with a twin needle no problem… well, no problem until today, when I am fighting tension and the machine keeps jamming, hence my ending up here – looking for hints, I am going to try your separate routes for each thread technique, so far I have just been threading both threads together…

  5. Hey Leah – I too love twin needles and one tip I used all the time (from helps when the knit hem gets all wavy as you sew it. Sandwich then fuse some soluble embroidery stabiliser into the folded hem, which makes it kinda stiff like light card, then sew away with your double needle. When you wash the garment, the stabiliser dissolves away and leaves a flat, stretchy hem. Its a little time consuming but worth it if you are having trouble with rib knits, for example, because the finish looks great.

  6. I’ve just started thinking about trying to sew with knits and will definitely try out the twin needle. Thanks for the tips!

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  8. Margaret Gorne said:

    THANK YOU, THANK YOU, THANK YOU! Your tips about adjusting the tension was exactly what I needed! Also. I loosened the bobbin screw, thus loosening the lower tension and my stitching was perfect! Nowhere in my Bernina manual or online on their website could I find anything helpful-you were a lifesaver!

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