The Ultimate Guide to Sewing With Stretchy Fabric

Stretchy fabrics have a reputation that scares many sewists away. You’ve probably heard the horror stories: wavy seams, skipped stitches, and fabric that stretches out of shape before you even finish your project. But once you know how to handle knits and other stretchy materials, they become some of the most rewarding fabrics to sew.

Welcome to the ultimate guide to sewing with stretchy fabric, where we’ll walk through everything you need to know.

Why Stretchy Fabrics Are Worth Your Time

Garments made from knit fabrics drape beautifully and move with your body. Unlike woven fabrics that rely on ease and darts for fit, stretchy materials do the work themselves. T-shirts, leggings, cozy cardigans, and athletic wear all look best when made from fabric that gives. Once you master the techniques we’ll go through below, you’ll open up a whole new world of comfortable, professional-looking garments.

Learn Your Fabric’s Stretch

First, you must examine the particular stretchy fabric you’re working with, as this determines how you’ll approach it.

The Direction

Stretchy fabrics behave differently depending on which way you pull them. Most knits stretch along the crosswise grain (from selvedge to selvedge) but have little to no stretch along the lengthwise grain. Some fabrics, like spandex blends, stretch in both directions (we call these four-way stretch fabrics).

Hold your fabric up, give it a gentle tug in different directions, and notice where it stretches most. This information determines how you’ll lay out your pattern pieces. Most garments need the greatest stretch to go around your body, so you’ll place pattern pieces with this in mind.

Stretch Percentage

Pull a 4-inch section of your fabric and see how far it stretches comfortably. Does it stretch to 5 inches? That’s 25% stretch. Does it reach 6 inches? You’re looking at 50% stretch. This measurement helps you choose appropriate patterns.

Recovery

After you release the fabric, does it snap back to its original size? Good recovery means your finished garment will maintain its shape. Poor recovery means you’ll end up with saggy knees on your leggings or a stretched-out neckline.

Equip With Essential Notions

Now, let’s get into the notions you’ll need to tackle stretchy fabrics.

Needles Made for Stretch

Your regular universal needles won’t cut it here. Instead, choose ball point, jersey, and stretch needles, which have a rounded tip that slides between the fabric’s fibers instead of piercing through them. This prevents snags and skipped stitches.

Keep a selection of sizes on hand. Typically, we use 70/10 for lightweight knits and 90/14 for heavier sweatshirt fleece.

Thread With Give

Cotton thread, while lovely for woven fabrics, lacks elasticity and can snap or pull at your fabric when your seams stretch. Conversely, polyester and wooly nylon thread have a tiny bit of give, making them perfect for stretch fabrics.

A Walking Foot

Your regular presser foot might push the bottom layer of fabric forward faster than the top layer, creating wavy seams. A walking foot feeds both layers through at the same rate. This tool alone will solve many of your stretchy fabric frustrations.

Tune Your Sewing Machine Settings

You’ve figured out how your stretchy fabric behaves, and you’ve equipped your sewing machine with the appropriate notions. Now, it’s time to make some machine adjustments that will help.

Stitch Selection

For stretchy fabric, you need stitches with built-in stretch. The lightning bolt stitch (a narrow zigzag), stretch stitch, or any of the decorative stretch stitches on your machine will work. We love a simple zigzag set to 2.5mm width and 2.5mm length for most projects.

Tension Adjustments

Slightly loosening your upper tension helps your stitches flow with the fabric. Test on scraps first—your stitches should lie flat without puckering. The bobbin thread shouldn’t show on top, and the top thread shouldn’t pull through to the bottom.

Presser Foot Pressure

Lightening the presser foot pressure prevents the feed dogs from stretching your fabric as it moves through the machine. Check your manual—most machines have a dial or switch that adjusts this pressure.

Beyond the Machine: Techniques That Prevent Problems

Your machine won’t be doing all the work. Here’s what you can do to prevent issues with stretchy fabric when you handle it.

Be Careful When Cutting the Pattern

Pin carefully or use pattern weights. Pins can distort stretchy fabric, so place them within the seam allowance. Pattern weights eliminate this problem entirely and speed up your cutting process.

When you cut, use sharp rotary cutters or scissors. Dull blades drag and stretch the fabric, throwing off your measurements.

Let the Machine Do the Work

Don’t pull the fabric through the machine. This stretches it out and creates wavy seams that won’t press flat. Instead, guide the fabric gently and let the feed dogs pull it through at their own pace.

Try the Finger Pressing Method

Place one finger behind the presser foot and one finger in front of it as you sew. Apply gentle tension to keep the fabric flat—but don’t stretch it. This technique keeps your seams straight without adding stress to the fabric.

Stabilize Problem Areas

Shoulders, necklines, and anywhere you don’t want stretch needs stabilization. We use clear elastic, twill tape, or strips of lightweight interfacing along these seams. This prevents your neckline from stretching out after a few wears.

Press With Care

Heat can melt or distort synthetic knits. Use a lower temperature setting and press with an up-and-down motion rather than sliding the iron. Additionally, use a pressing cloth to protect delicate fabrics. And never press directly on the right side of shiny athletic fabrics—you’ll flatten the finish.

Your Next Steps

Now that you’ve read this ultimate guide to sewing with stretchy fabric, it’s time to start practicing. After all, there’s only so much you can learn in the theoretical!

So buy a stretchy sewing fabric from Inspired To Sew and dive into a project. We suggest starting with something simple like a T-shirt or lounge shorts. It probably won’t turn out perfect the first time, and that’s okay. Just keep at it.

Each project will expand your skills and teach you something new about how these fabrics behave. You’ll develop a sense for which settings work with which fabrics, and those wavy seams that plagued your early attempts will become a distant memory. Best of luck!