Sewing with Knits
Updated: Jun 14
Sewing with knits can be daunting, but it doesn't need to be! Our children want to wear knits, and now with many more quality knits on the market you will love to sew with them. Here are several important tricks you need to know when buying and sewing with knits. So grab one of our many knit sewing patterns (like Kaki, Nora, or Bunny's Knit Nightie), your favorite knit fabric and dive on in!
Differences with Type of Knit
We recommend using interlock knits or knits with 35% or less stretch. Interlock knits are more stable, so they are a great choice for beginners.
To determine the stretch of your fabric, measure across the width of the knit 10” and mark with a pin. Now stretch that section and measure how far it will stretch. As an example, if it stretches to 12.5”, then the knit has a 25% stretch.
An interlock knit will lay flat and appear the same on both sides of the fabric. You will be able to see little Vs on both sides. The interlock knit will be thicker and will not have the same stretch recovery as jersey. This is often a good choice for a first time knit project.
A jersey knit will look different on the front (little Vs ) and on the back ( tiny “bumps” ). In the knitting world, the front would be called “knit” and the back would be called “purl”. You can also use the “roll test” to determine if it is a jersey knit. To do this test, pull across the cut end of the fabric, selvage to selvage. A jersey knit will roll very tightly and will not lay flat at all! This fabric will have more stretch and a great stretch recovery.
Best Notions to Use with Knits
Never use microtex sharp needles when sewing on knit. Sharp needles could cause a run in your fabric. A universal needle can be used on knit or woven fabrics. A ballpoint or stretch needle should be used on finer knits
Instead of a straight stitch, always use a stretch stitch (a specific stitch on some machines) or a small zigzag stitch width of 0.5mm and a stitch length of 2.5mm. Make sure to not stretch the fabric as you sew. Use a straight stitch for ease, gathering, or topstitching.
Always sew with polyester thread. Light weight cotton thread will break as the knit stretches.
Use a lightweight fusible interfacing on areas you don't want to stretch. Shoulder seams will not stretch out of shape if you fuse a 1” strip of light weight fusible interfacing to the wrong side of the shoulder edges before stitching.
Before You Sew
We highly recommend washing and drying the knit fabric before cutting. Knits will shrink, so it’s best to wash before you begin.
Most of a knit’s stretch is from selvage to selvage. (across the width of the fabric) So, when laying your pattern pieces on the fabric, take care that you place them with the grain line parallel to the selvage.
Knits often curl on the edges. After cutting your fabric from the pattern pieces, Spray the edges with spray starch and iron the edges dry. This should allow the edges to lay flat.
Whenever top stitching is called for, a twin needle will give a finished look and has built in stretch. I would recommend a needle width of 3.0/80 or 4.0/80.
Using a double needle is an easy-to-master skill that can add the perfect details to your project. The double needle’s stitch allows the fabric to stretch without breaking the thread. Choose a double needle appropriate for knit fabrics with a width of 2 – 4mm. You will need two spools of thread. If you do not have an extra spool, wind an extra bobbin to use. For instructions on how to use a double needle on your machine, refer to your machine’s user manual.
While knit’s raw edges will not unravel, we recommend finishing the seams for a professional look. For finishing knit seams, we recommend using a serger. The differential feed may need to be adjusted to a 2 so that the knit will not become wavy. Use a scrap of fabric to test this setting and refer to your serger manual. However, if you do not have a serger, you can use your sewing machine and zigzag the edges. Otherwise, you can leave seams unfinished and press seams open.
If your seams are a little wavy. Use a hot steam iron with a burst of steam to reshape them.
Tips by Susan Whitman
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