Tips for Sewing with Knit Fabric

Sewing with knit fabric can be a rewarding experience, but it can also present a unique set of challenges, especially for beginners. Knit fabrics are known for their stretch, flexibility, and comfort, which make them ideal for casual wear, activewear, and even formal designs. However, their stretchy nature requires a few adjustments in sewing techniques to ensure clean, professional results. Here are some essential tips to help you master sewing with knits:

Choose the Right Needle

Using the correct needle is crucial when working with knit fabrics. The best choice is a ballpoint or stretch needle. Unlike regular needles, these have a rounded tip that gently slides between the fabric's fibers without causing snags, pulls, or holes. For most knit fabrics, a ballpoint needle in size 70/10 or 80/12 works well.

Use the Right Stitch

Knit fabrics stretch, and so should your stitches. A regular straight stitch won’t allow your fabric to stretch, and this could lead to popped seams when the fabric is pulled. Here are a few stitch options:

• Zigzag stitch: A narrow zigzag stitch allows the seam to stretch with the fabric. Adjust the width and length of the stitch to suit the fabric’s stretchiness.
• Stretch stitch: Most modern machines have a stretch stitch setting, which is perfect for sewing knits. It looks like a lightning bolt and is designed to stretch with the fabric.
• Serger/Overlocker: If you have a serger, it’s a fantastic tool for sewing knits. It sews, trims, and finishes seams in one step and creates a professional finish.

Stabilize Your Fabric

Knit fabrics can be tricky to handle because of their stretchiness and tendency to roll at the edges. Stabilizing the fabric can make it easier to work with. Here’s how:

• Use fabric clips instead of pins: Pins can distort knit fabric by creating small holes or pulling it out of shape. Fabric clips are a better option, as they hold the fabric in place without affecting the material.
• Stay tape or interfacing: For areas like necklines, armholes, or hems, where you don’t want the fabric to stretch out, you can use stay tape or lightweight fusible interfacing. These help maintain the shape and prevent the fabric from becoming too loose or wavy.

Presser Foot Pressure

Knit fabrics can get stretched out if too much pressure is applied by the presser foot. Many sewing machines allow you to adjust the presser foot pressure. Try lowering it slightly to prevent your fabric from stretching or rippling as you sew. Test on a scrap piece of fabric to find the right setting.

Test on Scrap Fabric First

Before starting on your actual project, it’s always a good idea to test your stitch and settings on a piece of scrap fabric. Knit fabrics can vary widely in terms of stretch and thickness, so a test run can help you fine-tune your needle, stitch type, tension, and stitch length before diving into your project.

Use a Walking Foot

A walking foot, or even-feed foot, helps feed both the top and bottom layers of fabric through the machine at the same rate. This can be particularly helpful for knits, which have a tendency to stretch unevenly when sewn. It helps prevent puckering, stretching, or waving in seams.

Avoid Stretching the Fabric While Sewing

It can be tempting to pull or stretch knit fabric while feeding it through the machine, especially if it’s curling at the edges. However, this can cause the fabric to become misshapen or create wavy seams. Let the machine do the work of moving the fabric, and keep it relaxed as you sew.

Use Stretch Thread (Optional)

Regular polyester thread works well for most knit fabrics, but if you want extra stretch in your seams, you might consider using a stretch thread in the bobbin. This can help maintain the elasticity of the seams and is particularly useful for very stretchy fabrics, like spandex or Lycra.

Finish Seams Properly

Knit fabrics don’t fray in the same way woven fabrics do, but finishing seams can still improve the durability and look of your project. A serged edge is ideal, but if you don’t have a serger/overlocker, you can use a zigzag stitch along the raw edge to finish the seam and prevent it from curling.

Press as You Go

While knits generally don’t need as much pressing as wovens, it’s still important to press your seams as you sew. Use a low heat setting and be gentle to avoid stretching or damaging the fabric. Pressing helps your seams lie flat and gives your finished project a professional look.

Sewing with knit fabric can open up a whole new world of possibilities for your sewing projects, from comfortable t-shirts and leggings to dresses and jackets. With the right tools and techniques, sewing knits can be just as easy—and enjoyable—as working with woven fabrics. By following these tips and practicing on different types of knits, you'll quickly gain the confidence to tackle any stretchy project that comes your way!