Garments sewn from knit fabrics are comfortable to wear, relatively easy to fit and generally don’t need fiddly closures, which makes them quick and gratifying sewing projects. However, they have different characteristics compared to woven fabrics that you should be sure to consider when learning how to hem knit fabrics.
Let’s look at different ways to hem knit fabric for finished garments.
Hemming knits are often the trickiest part because you need to make sure the openings to your garment stay stretchy enough to pull on and off your body. If you hem knit garments in the same way as you would a woven garment, the fabric may become wavy or the stitches may pop when you try to stretch the garment over your head.
There are a few general rules for hemming knit fabrics, regardless of which technique you use:
- Knits do not fray like woven fabrics do, so you only need to turn the hem under once.
- When sewing knits, always use a ballpoint or stretch needle in your machine, which will glide through the looped knit fabric without piercing and breaking the fibers.
- If you have one, use a walking foot on your machine. The two layers of fabric feed evenly under the foot, which results in a flat, instead of wavy, hem.
- Stabilizing the knit fabric you’re going to hem will significantly improve the outcome, especially if your knit fabric is lightweight. There are several options for stabilizing, such as fusible elastic interfacing, fabric spray starch, wash-away or tear-away stabilizers, and knit stay tape. Choose something that will slightly stiffen the fabric, making it less likely to curl, stretch out under the presser foot, or get sucked into your feed dogs, while maintaining the stretch of the fabric. Below I have attached a strip of fusible elastic interfacing before turning up the hem of this cotton jersey fabric:
1. The zigzag stitch
The nature of the zigzag stitch allows the thread to stretch with the fabric. Turn the hem up the desired amount, then use a zigzag stitch to secure it. A narrow zigzag stitch is less noticeable. Again, this stitch is most successful if you stabilize the fabric and use a walking foot. You can see the difference in hem waviness below:
2. Double needle
To achieve a more professional-looking hem without professional equipment, turn up the hem and sew with a double-needle (also called a twin needle) from the right side of the fabric. The bobbin thread will zigzag between the parallel stitches, resulting in a stretchier hem.
If you have a serger, you may opt to first serge along the raw edge before turning up the hem so the underside looks like more like a professionally cover-stitched hem, assuming the thread colors match!
3. Stretch stitch a blind hem
You may have sewn a blind hem on woven fabrics, but you can also use a variation of this stitch on stretchy fabrics. Many modern machines have this stitch function, which is essentially a zigzag blind stitch. This creates a hem that is attached to the garment in intermittent stitches, so the stitches are less visible (as long as the thread color matches the fabric). This hem is ideal for garments such as knit pencil skirts or unlined knit blazers, where you want a more polished finish than you would on more casual knitwear.
First, press up your hem as usual. Then fold the hem back towards the right side of the garment, leaving a narrow edge of the hem that will be sewn on.
You can use a blind hem foot on your machine if you have one, but it’s not required. Test on a scrap how wide to make the stitch and where to position your needle. From the wrong side, sew along the exposed hem edge, making sure the wide zigzag catches the fold of the garment every few stitches. Press the hem down.
4. Fabric bands
If you are a sewing a knit top and would prefer to hide all your stitching, you can finish the sleeves and/or bottom hem with a separate folded band of fabric. The fabric doesn’t have to be stabilized for this finish.
Measure the circumference of the opening to be hemmed. Cut a separate rectangular piece of fabric (making sure the stretch is going the same way as the stretch of the garment) that is slightly smaller than your garment opening. This will ensure that the bands won’t get baggy after pulling them over your hands or shoulders.
Now serge or zigzag stitch the short edges of the band together. Fold the long edges of the band wrong sides together. Serge or zigzag stitch both layers to the right side of the garment, matching seams. Press the band down.
The coverstitch is the ideal way to hem most knit garments, and you will typically see this finish on store-bought knitwear such as t-shirts and leggings. The right side features parallel rows of straight stitching, with the underside in a loop of thread that allows maximum stretch. You need a specific machine for coverstitching, however, which makes it the least accessible option. Many higher end models of sergers have a coverstitch function that requires a slightly different threading and blade configuration. There are also stand-alone coverstitch machines available for home sewers to purchase.
If you’re new to coverstitching, it is covered more in-depth in the Craftsy class, Creative Serging: Beyond the Basics.
This sewing technique works similar to the double-needle finish, except you have the ability to adjust the differential feed, so the fabric doesn’t stretch out as you sew. Simply press up the hem and coverstitch from the right side of the garment. Admire your pro finish!
As you can see, hemming knits is really not any more difficult than hemming woven fabrics. Hopefully, these techniques will help you easily finish off your knit garments so you can wear them with confidence.