How to Sew Stretchy Fabrics Without Losing Your Mind

I love sewing with spandex, cotton jersey, and other stretch fabrics. They're incredibly comfortable to wear, and garments made from knit fabric have a natural ease that woven fabrics just can't match. But sewing stretchy fabric does come with a learning curve.

The good news: there are a few simple tricks that make all the difference. Here's what you need to know.

1. Use a Ballpoint or Stretch Needle

This is the single most important rule for sewing with knit and stretch fabrics. A universal needle is too sharp — it punches through the fabric and can leave holes, snags, and runs that you cannot fix.

A ballpoint needle has a slightly rounded tip that slides between the fabric loops rather than piercing them. It works well for most knit fabrics. For highly elastic fabrics like spandex or four-way stretch, a stretch needle is even better since it's designed to handle the extra tension without skipping stitches.

For the most polished look on hems, a stretch twin needle creates two parallel rows of stitching on the right side with a zigzag stitch on the underside that allows the hem to stretch. It's a game changer for a store-bought-looking finish.

Also: use ballpoint pins for knits so you're not creating holes in the fabric before you even start sewing. Keep them on a separate pin cushion so they don't get mixed up with your regular pins.

2. Choose a Stretch Stitch

A straight stitch has no give. When you stretch the fabric and wear a garment, those straight stitches will pop. You'll also often end up with wavy, rippled hems if you use a straight stitch on knit fabric.

Instead, select a zigzag or another stretch stitch on your machine. Most sewing machines offer several options:

• Zigzag stitch (my go-to)

• Lightning bolt stitch

Before you start sewing with any zigzag or stretch stitch, check that your needle will clear the presser foot. The wider needle path can cause a broken needle if you're not paying attention.

A walking foot also helps enormously when sewing knit fabrics. It feeds the top and bottom layers of fabric at the same rate, preventing the stretching and shifting that causes uneven seams.

3. Use Polyester or Stretch Thread

Cotton thread breaks too easily with stretch fabrics. Always use polyester thread when sewing knits.

If you really want to use a straight stitch for a project, there's a trick: stretch thread in the bobbin. It provides enough elasticity to let a straight stitch survive the pull of stretchy fabric without popping. Wooly nylon is another great option that works similarly.

A few tips if you try stretch thread:

• Wind it into the bobbin by hand rather than using the machine winder

• Use a slightly longer stitch length than usual

4. Stabilize Your Seams

When you're getting wavy seams despite doing everything else right, stabilizing the fabric can help.

Fusible tricot interfacing is the best interfacing option for stretch fabrics because it has its own stretch built in. It won't fight the fabric the way a non-stretch interfacing would. Apply it to seam areas that are giving you trouble.

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Knit stay tape is a lighter-weight alternative that's faster to apply. You sew it into the seam allowance as you stitch, and it prevents the seam from stretching out over time without adding bulk.

Stretchy fabrics can be intimidating at first, but once you have the right needle, the right stitch, and the right thread, they're genuinely fun to work with. The comfort of a finished knit garment makes it all worth it!

Have any tips of your own for sewing stretch fabrics? Drop them in the comments below!