Fabric 101: Spandex (aka Elastane or Lycra)

Spandex is an entirely synthetic fiber that’s known for its incredible ability to stretch in any direction. With spandex, it’s the actual yarns that the fabric is made of that allow it to stretch, rather than the weave. When you think of spandex fabric, the garments that come to mind are tight athletic wear or swimwear, or form-fitting undergarments. 

However, spandex is rarely used in isolation. Usually, small percentages of spandex fibers are added to many other types of fabric to make them stretch more too. Simple cotton shirting with only 5% spandex or elastane suddenly becomes quite stretchable. 

Spandex is the general term used for this type of elastic fabric in the US, whereas elastane is more commonly used in the EU. Lycra is a trademark name for this type of fabric produced by the DuPont Corporation.

Fabric	Spandex (also known as elastane and Lycra)
Texture?	Smooth, plastic-like texture
Stretch?	Highly stretchy, greater than 100% stretch
Heavy or light?	Somewhat lightweight fabric
Stiff or drape?	The drape is somewhere in between flowy and stiff
Nap?	No nap
Typical fiber content?	A type of synthetic fiber known as polyurethane (often the fiber is also referred to as spandex or elastane)
Opaque or sheer?	Opaque fabric
Shiny?	Some shine or sheen
Fraying?	Spandex fabric does not fray
Pilling or pulling?	Resistant to pilling and thread pulling
Cool or warm weather?	Can be used for either, often better for cooler weather because spandex is not very breathable
What to make?	Most frequently used for athletic and activewear clothing
What needle to use?	Use stretch needles with spandex (usually size 70 or 80)

What kind of fabric is spandex?

Spandex is a type of fabric that is thin and highly elastic. While 100% spandex is rare, generally any fabric that has more than 50% spandex is called a spandex fabric. It is most often used for activewear, bodysuits, and undergarments.

Spandex is most known for its extreme stretchability, sometimes being able to stretch more than 5 times its original length. It also gives fabrics high flexibility in all directions, not just crosswise. 

What can you make with spandex fabric?

Spandex fabric is most often used for form-fitting activewear, including cycling clothes, leotards, swimwear, leggings, and more. It’s also used for form-fitting undergarments, like sports bras and shapewear, as well as costume garments like spandex superhero suits.

Properties of spandex knit fabric

• Texture: Spandex has a smooth, plastic-like feel to it. Types of fabric that have spandex blended into them will often take on some of the texture of spandex, becoming a little smoother than the fabric originally would be without it.
• Stretch: Spandex is known for being the stretchiest type of fabric you can get. Standard spandex will usually have at least a 4X stretch to the material, and you can find some fabrics that stretch up to 7X or 8X. Spandex fabrics are almost as stretchy lengthwise as they are crosswise.
• Weight: Spandex is a fairly lightweight fiber that doesn’t add much weight to the fabric composition.
• Opacity: Spandex fabric is generally dense enough that it will be opaque.
• Shine: Most spandex that I’ve come across has a slight sheen to it. It’s not a glossy or reflective shine, but the fabric is also not matte.
• Pilling: Spandex is resistant to pilling and ripping. 
• Wrinkling: Like most synthetic materials, spandex is highly wrinkle-resistant.
• Breathability: Spandex is not very breathable. However, the moisture-wicking properties of the material can still make it appropriate for sportswear clothing that you’ll be sweating a lot in, even in the summer.

How to sew with spandex fabric

Like most knit fabrics, spandex is fairly difficult to sew. I recommend learning about how to sew with knit fabrics in general before picking up spandex as your fabric of choice.

The first obstacle comes when the fabric stretches out as it moves through the feed dogs of your sewing machine. This can lead to ugly, wavy seams that will never sit flat. If you don’t have a serger (or overlock machine), you can still solve this problem by testing out different ways to stabilize the fabric and keep it from stretching out:

• Try installing a walking foot on your sewing machine
• Use a knit presser foot
• Apply wash-away tape to the seam before sewing
• Place a piece of tissue paper on top of the seam as you sew

The other problem I come across with spandex fabric is frequently skipped stitches. To solve this problem try:

• Use a stretch needle
• Switch to a different-sized needle (if you’re using 80 now, try switching to 70 or 90 to see if it makes a difference)
• Adjust your machine settings (thread tension, presser foot pressure, and stitch length)
• Place a piece of tissue paper over the seam (this is what I do as a last resort, but it almost always works)
• Use a stretch stitch with your spandex fabric. This means using a zigzag stitch setting or the lightning bolt stitch.