How to use a twin needle

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This ever happened to you?

You’ve almost finished sewing, and there’s only the hem left to sew. Soon you’ll finally wear your new super comfy knit top; the only thing you need to finish it is to use a twin needle.

But when you inspect the seam, you find it’s so wobbly it looks like you sewed it after that party last Saturday. Uneven seams, skipped stitches, and wrinkles everywhere. 

You feel like crying.

Is this destined to be another contribution to the “I’ll never get caught with that in public” pile of shame?

How about learning how to use that twin needle once and for all?

Don’t worry; it’s not that hard if you only give it some practice.

Topstitching is not only a practical way to hem; it’s also decorative and a straightforward way to add a Ready-To-Wear look to your garments. But getting those rows straight and neat can be a discouraging task, especially if you use a regular sewing machine. 

Uneven hemlines and skipped stitches give poor quality seams that break easily. An overall crappy DIY look is not really what you strived for when you started sewing this garment, was it? 

So, do you have to accept The Macabre Ridge Syndrome-look on your hems? I don’t think so. You just need some preparation, a twin-needle, and a couple of good advice and. So I guess this is your lucky day 😉 Read on, my friend, let’s get on top of those rows of stitches.

Before you jump in

Let’s have some gear talk, shall we?

The solution to a professionally looking topstitching when you don’t have access to a coverstitch machine is the twin needle. There are a few things to consider when choosing what needle to use, so let’s start with the basics.

What is a twin needle?

A twin needle is composed of two needles attached to one shaft, making it possible to sew two identical rows of stitches simultaneously.

Different types of twin needles


Why use a twin needle?

If you don’t own a coverlock machine, using a twin needle is the perfect alternative to achieve a professional-looking seam. At first, it can be a little tricky, but when you nail the technique, using a twin needle will save you about half the time when you want topstitching on your garment.


When to use a twin needle?

It’s commonly used for topstitching around the sleeve edges and hem. But you can use it for some of your sewing machines’ decorative stitches, too, as long as you have the throat plate and presser foot to accommodate for the width of the stitch and the two needles.


Substitutes for a twin needle 

You can use a regular needle and make a single row of stitches, but that doesn’t replicate the ready to wear look we’re going after in this post. 

It’s also possible to sew two parallel rows of stitches with a regular needle. The challenge is to keep the same distance between the rows all around the edge of the fabric. 

I’m not saying it’s unachievable, but I wouldn’t recommend it. You’ll find that the price of a twin needle is worth the time and agony you save.


Twin needles for different kind of fabrics

You can use a twin needle on both knit and woven fabrics. If you look at the seam, you see the threads are crisscrossing on the back of the fabric. This makes the seam stretchy and ideal for hemming garments in knit fabrics like jersey, ITY knit, and stretchy knits for activewear.

View of the seam on the back of the fabric


Types of twin needles

Twin needles come in different sizes and widths, from size 1.6/70 for fine fabrics like chiffon and silk to 6.0/100 for heavy-duty fabrics like denim and lofty wools.

  • Universal twin needle – Use for woven fabrics.
  • Jersey or Ballpoint twin needle – Use for stretchy fabrics and knits.
  • Jean twin needle – Use for topstitching with a heavier weight thread on sturdier fabric.

“Match the needle to your fabric type and weight, or you’ll go bananas.”


Getting prepared

Check your sewing machines’ throat plate and presser foot width (use the ones you use for a zigzag stitch). 

You do it by “walking” the stitch manually, completing a couple of stitches with the handwheel on your machine. This is especially useful if you’re sewing a decorative stitch with some width. 

The point is to make sure the needles fit into the opening of the presser foot and throat plate through the whole width of the stitch, so it’s wide enough that the needle won’t touch the presser foot when you sew.

Inserting the needle

Insert the twin needle with the groove facing you and the shank’s flat side facing away from you. Make sure the needle is attached all the way up in the needle bar. A stable needle gives the smoothest stitches, and you don’t want the needle to slide out during sewing, safety first!

Front and back views of a twin needle



If your machine has an extra spool pin, you can use it for the second spool of thread. If not, you can either use the bobbin threader pin or sew with two bobbin spools with matching threads on the same spool pin unwinding the thread in opposite directions. 

Double thread spools for threading

Thread one spool at a time, as usual, except for the last step, where you let the second thread run outside the last thread holder, making sure the two threads don’t tangle.

View of a threaded twin needle

If you want to have a more detailed look, here’s a handy video on how to thread a twin needle by Threads Magazine.

Different types of twin needle seams

Straight seams

Make a couple of back stitches at the beginning and end of the seam.

Sew with the right side of the fabric facing you.

Sew slowly and steadily, and do not stretch the fabric. A magnetic seam guide can do wonders and function as a “third hand.”

Curved seams

You sew a curved seam the same way as a straight seam.

Keep an extra eye on the outside edge of the fabric, so you make an even seam.

Sewing corners

You can’t get an exact angle on the row of stitches when you turn a corner with a twin needle because the threads will cross each other. Nevertheless, there is a way to sew a corner if you’d like; 

Sew the first line of stitches all the way to the end and off of the fabric. Cut the threads, turn your work and stitch the next row, crossing on top of the first one at a 90-degree angle. 

A fabric swatch corner sewn with a twin needle


Twin needle troubleshooting

The 3 common errors when using a twin needle:

  1. The fabric between the stitched rows forms a ridge.
    Fix by loosening the thread tension, and sample the seam on scrap fabric until your happy with the result.
  2. The needle skip stitches.
    Fix by using stabilizers like fusible tape or interfacing. Make sure both needles stitch through the enforced fabric, or you’ll end up with a ridge.
  3. You end up with wobbly stitches.
    Fix by using a fabric guide. To keep an even distance to the fabric edge, you can use a magnetic fabric guide or the quilting arm that came with your sewing machine. You can also place a piece of tape at the right distance from the needle and guide the fabric with your hands. With the tools, however, it’s much easier to get a great result.



Sometimes it’s practical to pre-press your hem before you sew especially if it’s a rounded edge, but it’s not always the case. Test your seams on scrap pieces of the same fabric you’re sewing, and you’ll be sure what works best.

Use a stabilizing tape the same width as the hem and fuse it right at the fabric’s edge. Then it’ll be easy to simply fold the tape under and topstitch from the right side following the edge of the tape.

Now it’s your turn!

It may seem complicated to get those seams perfect from the start but have faith. Go slow, and test every seam on scrap fabric first, and you’ll master the twin needle in no time.

Having self-made garments that look like Ready-To-Wear makes them all the more enjoyable to wear, and your confidence working the twin needle will grow by the garment. 

Now, I’d love to see the results of your practicing what you’ve learned.

Why not have a go on the Alissa racerback tank top?  

Sew great!

Make any pattern work for you no matter what body type, size or style.

I’ve created a process you can follow so you can wear anything you’d like. Because when you sew you rock, and so can your clothes.

Get your FREE workbook here

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