Basic Sewing Tips and Choosing Thread and Fabric for Sewing Lycra

Choosing Thread for Stretch Sewing

When choosing thread for sewing stretch fabrics use the best quality thread you can find. Stretch seams take a lot of punishment, particularly if used for gymnastics, dance, swimwear or active wear. The stronger your thread, the stronger your seams will be. This is not the place to save a few dollars by choosing cheap thread. In choosing thread for my machines:

  • I use Gutermann brand thread in my sewing machine, but any high quality brand thread will work equally well. 
  • I use Wooly Nylon or similar thread in the loopers of my overlocker/ serger. This gives the seams a soft, stretchy finish.
  • I use Gravity Core thread in the needles of my overlocker/ serger, but any high quality thread will work well.

Choosing fabric for Stretch Sewing

There are a number of different styles of fabrics that can be used for sewing activewear.  Stretch fabrics are generally described as either 2-way or 4-way stretch.

  • A 2-way stretch fabric will stretch across the grain of the fabric (from left to right). It will not stretch along the grain of the fabric (from the top to the bottom of the fabric). 
  • A 4-way stretch fabric will stretch both across the grain of the fabric (from left to right) and along the grain of the fabric (from the top to the bottom of the fabric). 

Most activewear garments will be more comfortable when made from 4-way stretch fabric but you can often get away with using 2-way stretch fabric for active wear separates. 

Stretch fabrics can be made from either natural fabrics such as cotton or bamboo or synthetic fabrics, such as nylon or polyester. They will be blended with a synthetic stretchy fabric, such as lycra, spandex or elastane. This helps the fabric to recover to it's original size after it has been stretched. Generally speaking the higher the lycra, spandex or elastane content, the better the fabric will recover after it has been stretched.

  • As a general rule, for leotards aim for fabrics with 15-20% added lycra or spandex (you can often get away with less stretch if you need to but you may need to adjust the sizing. Let's face it some fabric is perfect and irresistible and totally worth sewing the garment a size larger to use).
  • Avoid using stretch fabrics that do not have lycra, spandex or elastane to sew active wear garments.
  • If sewing swimwear, aim for a synthetic fabric such as nylon lycra or polyester spandex. Chlorine from swimming pools is particularly harsh on fabric, however, there are fabrics specially designed to be chlorine reistant, using these fabrics will help your swimsuits last a lot longer.
  • When starting out sewing active wear it can be tempting to use the cheapest fabric you can find to practice on. Be aware that poor quality stretch fabrics can be very difficult to sew. They are more likely to be thin, slippery, stretch out of shape and curl at the edges making everything far more challenging than it needs to be. I recommend aiming  to get fabric that is a reasonable weight and quality as this will make everything so much easier when learning.

Sewing with Stretch Fabrics

  • Sew all seams using either a zigzag stitch on your sewing machine or with an overlocker or serger. 
  • If using a sewing machine, generally a medium length and width zigzag stitch works well on stretch fabrics. A second row of stitching alongside the first row will provide extra strength. 
  • When using an overlocker or serger, seams can be sewn using either 3 or 4 threads. Generally, a 4-thread stitch provides stronger seams, but a 3-thread stitch is stretchier. 
  • Topstitch using either a zigzag stitch on your sewing machine or a coverstitch.
  • Many stretch fabrics do not fray. If using a fabric that does fray finish the edge with a zigzag stitch on your sewing machine or with your overlocker/ serger to prevent fraying.
  • The first time you use a new fabric sew a sample seam, stretch it hard and if the threads break adjust your stitch length or width (or adjust the tension on your overlocker or serger). Repeat this process until you can stretch the seam without your threads breaking.