Sewing with stretchy knit fabrics can be intimidating, especially if you're used to working with stable wovens on your trusty lockstitch machine. However, with a few simple adjustments and techniques, you can achieve a professional finish on even the stretchiest of knits. Here's how to make your lockstitch machine work for you, not against you, when sewing knits.
Choosing the Right Needle and Thread
Before you start sewing, it's essential to choose the right needle and thread for your project. For most knit fabrics, a stretch or ballpoint needle is the best choice. These needles have a slightly rounded tip that glides between the fibers of the knit, reducing the risk of skipped stitches or fabric damage. As for thread, opt for a high-quality, cotton-wrapped polyester or 100% polyester thread that's designed for sewing knits. These threads have a bit of give, allowing them to stretch with the fabric and reducing the likelihood of thread breakage.
Adjusting Your Stitch Length and Tension
To sew knits successfully on a lockstitch machine, you'll need to adjust your stitch length and tension. A longer stitch length (around 3-4 mm) will give you a more flexible seam that can stretch with the fabric. You may also need to loosen your top tension slightly to prevent the thread from puckering or breaking.
Using a Stretch Stitch or Zigzag Stitch
While a lockstitch machine isn't equipped with a built-in stretch stitch like some sergers or overlock machines, you can still achieve a similar effect by using a zigzag stitch. Set your machine to a moderate zigzag stitch (around 3-4 mm in width and 3-4 mm in length), and you'll be able to sew a seam that can stretch with the fabric. If your machine doesn't have a zigzag stitch, you can also try using a simple straight stitch with a slight adjustment to your sewing technique (more on that below).
Techniques for Sewing Knits on a Lockstitch Machine
Stretching as You Sew
One simple technique for sewing knits on a lockstitch machine is to gently stretch the fabric as you sew. This will help the seam stretch with the fabric, reducing the risk of popped stitches or seam failure. To do this, hold the fabric in front of and behind the presser foot, gently stretching it as you guide it under the needle.
Using a Walking Foot or Teflon Foot
A walking foot or Teflon foot can be a huge help when sewing knits on a lockstitch machine. These feet are designed to help guide the fabric smoothly under the needle, reducing the risk of bunching or distortion. They're especially useful for thicker or more textured knits.
Sewing with a Slightly Looser Tension
As mentioned earlier, loosening your top tension slightly can help prevent thread breakage and puckering when sewing knits. However, be careful not to loosen it too much, or you may end up with a sloppy or uneven stitch.
Tips for Finishing Seams on Knits
When sewing with knits, it's essential to finish your seams to prevent fraying or unraveling. Here are a few simple techniques for finishing seams on knits:
- Use a serger or overlock machine to finish the seam allowance, if you have one.
- Zigzag stitch along the raw edge of the seam allowance to prevent fraying.
- Use a simple straight stitch along the raw edge, then fold the seam allowance to one side and topstitch in place.
Putting it All Together
Sewing stretchy knit fabrics on a lockstitch machine requires a few simple adjustments and techniques, but with practice, you can achieve a professional finish on even the most challenging knits. By choosing the right needle and thread, adjusting your stitch length and tension, and using a stretch stitch or zigzag stitch, you'll be well on your way to creating garments that are both comfortable and durable.