Sewing in knit fabrics

Intro to knit fabrics

There are so many different knit fabrics! Jersey (viscose, cotton, tencel etc); college; french terry; interlock; ribbing; and so on... These fabrics are so much fun to sew! I'd say they are more forgiving than non-stretch fabrics since the sewn garments will shape with the body.

There's no fraying with knit fabrics, which means that you don't have to finish seams, which you would do with woven fabrics. Neither does knit get wrinkly, as much as woven fabrics usually do. They do shrink when washing for the first time, so you'll want to pre-wash the fabric before cutting into it.

Knit fabrics can have different amounts of stretch. For example, generally ribbing has a lot of stretch, while jersey and interlock has less. But it depends on if and how much lycra (elastane) is in the fabric. 

It's a good idea to evaluate the stretch of the fabric before sewing. For some sewing patterns the amount of stretch needed in the fabric is specified. Download my free stretch guide. 

Sewing machine or serger?

When you're sewing in knit fabric, a serger (overlocker) is great to use. But it's not necessary and you can achieve really nice results with a regular sewing machine too. These are my 6 best tips!

 

1. Use the correct needle

The most important thing is to switch out your universal needle on the sewing machine for a stretch needle. They have a rounded tip which won’t ruin the fabric. The same goes for your twin needle, if you’re using one. That one should also be stretch.

2. Use a stretch stitch

This is really important, especially for horizontal seams where stretch is needed (e.g. the neckline). A seam that doesn’t require much stretch, e.g. vertical seams such as the side seams, can be sewn with a narrow zigzag stitch.
A: Overlock stitch, for that you will need an overlocker/serger.
B: Narrow zig zag stitch (approx. 1,5 mm wide and 1,5 mm long). 
C: Normal zig zag stitch (approx. 2,5 mm wide and 2,5 mm long).
D: Twin stitch (switch out the needle for a twin needle, and use a stitch length of approx. 3 mm).

3. Don’t pull the fabric 

Try not to pull the fabric as you’re sewing. That generally results in a wavy seam. Neither should you let the fabric hang down from the table. Lift it up so that it can be easily fed into the machine.

4. Press seams

Always press a seam after you’ve sewn it. Don’t wait until the entire garment is finished. Pressing is often the thing that takes away that “homemade” look and gives the garment a professional feel. When you’re pressing, the thread “melts” into the fabric.

5. Use a walking foot

If none of the above helps you could switch to a walking foot (B) instead of a regular presser foot (A). It makes sure to evenly feed the fabric and keeps it from stretching as you sew. I often use my walking foot, especially for topstitching.

6. Adjust the presser foot pressure

Does the fabric's edge get stretched and rippled after you sew? Try lowering the pressure of the presser foot. This will keep the foot from holding the fabric back, preventing the fabric from stretching as it moves under the presser foot.