My Best Tips for Sewing Sweater Knit Fabrics

Use sweater knit fabrics to make clothing such as cardigans, sweaters and jackets. Make it easy with tips to successfully sew with sweater knit fabrics.

Hey y’all, today I want to talk about sewing sweater knit fabric, since it’s one of the suggested fabrics for one of my patterns, the Sora Sweater. Below you can see one view of the Sora sewn in a lightweight brushed cotton/polyester blend french terry sweater knit.

The Sora Sweater samples sewn for the listing (modeled by Courtney of Sweeter Than Cupcakes Blog) feature sweater knits. Also sometimes called Hacci or Hatchi sweater knits, these fabrics are the closest you can get to a hand knit sweater without actually knitting it.

The sample fabrics I used were a navy blue heather warehouse purchase (similar here, affiliate link) and the gray was a purchase from Raspberry Creek Fabrics.

What are sweater knits?

All knit stretch fabrics are formed by with a single yarn formed into loops. You can see a demonstration of me knitting in this post on stretch fabrics. The difference in knit fabrics like jersey vs sweater knit is in the size of the yarn or thread used to make them and the size of the loops. In knitting this is referred to as the gauge. Jerseys are made with very fine yarn and small loops, and sweater knits are made with thicker yarns and larger loops.

Let’s also remember the difference between fabric and fiber. All knit fabrics, including sweater knits, can be made from fibers ranging from cotton, wool and linen to synthetic fibers like polyester and nylon.

But as lovely as sweater knit can look in finished products, it can also be one of the harder knit fabrics to work with. The larger loops can result in a less stable fabric. Sweater knits are prone to easily stretching under the presser foot of your sewing machine and growing while they’re worn. So today I’m sharing tips on sewing sweater knit for a beautiful finished result.

You can see a video covering my tips for sewing sweater knits below or on YouTube here, and there is even more information within this post.

Tip #1 Finish the Fabric Edges

First, unlike most knits, some sweater knits are prone to unraveling or fraying due to the looser knitted fabric structure. If that is happening to your sweater knit, it’s a good idea to finish edges with a serger or a faux overlock. To faux overlock, use a zig-zag stitch set to a wide width and short stitch length with one side of the stitch falling just over the edge of the fabric. This will help with all the little fuzzies that sweater knit can shed at first.

You might also find it helpful to reduce the pressure on your presser foot if that’s an option on your sewing machine. It can help keep edges and seams from stretching out. A walking foot can also be useful when working with sweater knits for the same reason. If you’re on a serger, play with your differential feed and a scrap of fabric if the stitch is stretching out the fabric.

Tip #2 Stabilize the Edges

The same looser knitted structure means that sweater knits generally have beautiful drape, but it also means that the fabric can have a tendency to grow. To help support the fabric and prevent this, I like to turn to fusible interfacings. Cut knit interfacing strips about 1/4 inch wider than the seam allowances for a pattern. Then fuse a strip along each of the raw edges of my pattern pieces.

This gives the seams a little light structure and helps keep the finished garment from growing longer as you wear it. Note that the stretch direction of the interfacing should be the same as the direction of greatest stretch on your fabric.

Other options for stabilizing seams in sweater knits (all knits, really) are to sew clear elastic or twill tape into the seams, especially the shoulder seams.

Tip # 3 Thread Marking Sweater Knits

Marking can be a problem on sweater knits – typical marking tools like chalk and tracing paper don’t work well on the thicker, loosely knitted yarns. So thread marking is a good tool to have in your arsenal.

To thread mark, you’ll take at least one stitch (from front to back and back up to the front side) through whatever you’re trying to mark – pattern and fabric. Use a contrasting thread and hand sewing needle. Then cut the thread and carefully pull the pattern off. The thread remains, marking the point on the fabric.

Tip #4 Use a Knit Picker to Fix Snags

A knit picker (affiliate link) is a tool to repair your sweater knit if it snags, which can happen during the sewing process or after while wearing the garment. It’s essentially a smaller version of a latch hook. To use it, you push the knit picket in from the wrong side of the fabric with the hook open and catch the pulled thread in the hook. Then pull the snag to the wrong side of the fabric and watch it disappear.

Tip #5 Use a Pressing Cloth

Finally, sweater knits often have nylon as part of the fiber content. So pressing with a pressing cloth is essential so that you don’t melt the nylon and ruin your project.

There you have it – 5 tips for sewing with sweater knits!