A Guide to Coverstitch Machines

Video Transcript

Have you ever wondered what machine creates the hems on your RTW t-shirts? It’s a coverstitch! A coverstitch is a specialty machine that’s primarily used for hemming knit garments. It creates stretchy stitches and it covers the raw edge of a hem all in one pass. If you sew a lot of knit garments and you want to create hems without using a twin needle or a zigzag stitch, you might want to invest in a coverstitch machine. Not sure if you want to invest in a totally separate machine for finishing knits? Watch this video to see if you’d find a coverstitch helpful.

In this video, I’m going to cover what stitches most coverstitch machines can create, how to flat hem and hem in the round, and some troubleshooting tips.

Most coverstitch machines have the ability to sew with one, two, or three needles, plus a looper underneath.

If only one needle is used, then a simple chain stitch is created. This stitch can be used for binding, hemming, and topstitching - it's great for topstitching jeans!

If three needles are used, then three lines of parallel stitching appear on the right side of the fabric, with the looper producing a complex thread pattern on the reverse. This stitch can be used for hemming, decorative stitching, elastic, and to create mock flat lock seams.

By far the most common arrangement, is to use two needles to create a classic T-shirt hem look. As there are three needle positions, you can create a narrow or a wide 2-needle coverstitch.

Let's take a look at some basic hemming applications.

The most basic coverstitching involves folding over the hem of a flat piece of fabric to the wrong side, and coverstitching from the right side, catching the hem underneath.

To do this, start at one side of the project, and make sure both needles are either straddling the cut edge underneath or piercing both layers of fabric.

Start stitching, and stop when you reach the end of the fabric (or your desired point if you’re not hemming the entire length).

Raise the presser foot and ensure the needles are at their highest position. Wave a thin object between the foot and the feed dogs, pulling the needle threads out.

Cut the needle threads, then pull the fabric away from you and behind the presser foot, and cut the looper thread.

More often than not, you’ll be hemming fabric in the round, such as on a sleeve, neckline, or skirt hem. As with the flat hem, you’ll first need to fold and press the hem allowance to the wrong side of the fabric, pin in place, and coverstitch from the right side, catching the hem underneath.

Start at any point in the round hem, usually near a seam, such as in the inner leg or a mid-sleeve seam, making sure the needles are straddling the cut edge underneath, or that the needles will pierce both layers of fabric.

Start stitching, and when you come around to the beginning, overlap the previous stitches for a few stitches.

Raise the presser foot, and ensure the needles are at their highest position. Wave a thin object between the foot and the feed dogs, pulling the needle threads out.

Cut the needle threads then pull the fabric away from you and behind the presser foot to cut the looper thread.

This series of steps will pull the needle threads to the reverse of the fabric, where you should knot the end threads together to prevent unraveling.

Use a pin to carefully pull the beginning needle threads to the reverse. From the reverse, look for a little loop of needle thread at the base of each stitch, and pull through. Or if it’s in a hidden area, just cut these close to the fabric, as the stitches won’t unravel from the beginning.

You’ll occasionally need to unpick a overstitched hem, and while it looks like this would be a tedious task, it’s actually quite easy!

The most important thing to remember is that coverstitching can only be unraveled in the opposite direction of how it was stitched. This is why it’s important to always secure the threads from the ends of your coverstitching, but securing the threads from the start is largely aesthetic. If you’ve already secured these threads, start by cutting off your knot and pulling the needle threads to the right side of the fabric. With a seamripper, gently undo a few stitches so you’ve got enough length to hold onto, but don’t cut the threads. With the needle threads on the right side of the fabric and the looper thread on the reverse, grasp the needle threads in one hand, the looper in the other, and pull. The stitches should unravel.

Tip 1: Always thread the looper first, then the individual needles. These machines can be pretty sensitive, so make sure there aren’t any tangles and that every thread is in its proper place.

Tip 2: Most problems are cause by improper threading, or by a needle. If you’re experiencing issues, change needles and make sure they’re all the way up in their bar slots. It might seem like a big deal to rethread, but sometimes that’ll fix the issue!

Tip 3: Use the right needles. Just like a sewing machine, you’re going to get better results if you’re using needles that match your fabric’s type and weight.

Tip 4: If you’re experiencing tunneling, try loosening the looper tension until the fabric between the stitches lies flat. Tunneling can be a common issue with lightweight, or really stretchy fabrics so you also might need to try increasing the stitch length, lowering presser foot pressure, lowering the differential feed, making sure all the needles sew over both layers of fabric, and / or use a stabilizing material such as knit stay tape.

Tip 5: Document settings. Once you’ve found the best settings for a particular project, be sure to document them so you can reference them later.

Tip 6: Reuse thread! If you don’t have two matching spools or cones of thread for your coverstitch hems, take the regular thread spool and bobbin from your sewing machine to use as your two top threads, and use a neutral thread color in the looper.

Tip 7: If you’re getting wavy hems, your presser foot may be stretching the fabric as it stitches. Try loosening the presser foot pressure or fusing lightweight interfacing tape on the wrong side of the hem before stitching, or even basting the hem with the sewing machine first.

Now that you’ve seen an overview of the kinds of stitches that a coverstitch machine creates, all you have to do is decide if it’s worth the investment. If you sew a lot of knits, especially activewear, this machine is very helpful. If you’re more comfortable with a zigzag stitch or twin needle, then there might not be a need for you to buy an entirely separate machine.

Do you own a coverstitch machine, or are you thinking about buying one? Let us know in the comments what machine you own and what features are must haves! Happy sewing!