Spandex and Stretch (How to select the fabric for elasticity)

Is spandex stretchy? – Today this question feels like someone is asking, “Is the moon round ?” or if “an elephant is big”?. Everyone who knows something about clothes knows about the elasticity of spandex.

Spandex, the word itself, is an anagram for “expands,” so who doubts its stretchiness?

“Spandex has kept my derriere lifted, my tummy tucked, and my “gals” facing north (even after they started to head in the opposite direction). It has given me the confidence to strut my stuff even when I look more like a microwave-inflated marshmallow than a sexy, middle-aged mama.”

This is an excerpt from the book “Who stole my spandex” by Marcia Kester Doyle. It cracked me up (the whole book is funny), but so true. Spandex has been a xavier for a lot of us. 

It was in the late 1950s that the world woke up to this incredible synthetic fabric called spandex which hid a multitude of sins of our body in its very stretchy elastic fibers. Since then, every other fiber is adulterated with spandex fibers in the textile manufacturing stage, for all its worth.

The stretchiness of spandex is exploited to make high-performance activewear, millions of stretch denim, and countless other everyday wear garments.

Spandex is the generic name for a man-made manufactured synthetic fiber that stretches many times its length and comes back to the same shape. The term is mostly used in US and Canada.

Elastane is the name for stretch fiber in some parts of the world, like Europe. Essentially both spandex and elastane are the same.

Lycra® is a registered trademarked spandex product of Invista. A similar brand name in Europe is Dorlastan®.

Spandex may be used to make the garment on its own or added in small percentages to natural or synthetic fibers to provide the elasticity and ability to retain long-term shape features of spandex fibers to the garment.

How much does spandex stretch?

Stretchiness refers to the quality of something growing larger than its resting state. But if a yarn just stretches, it will not be as useful and valued. The next best thing about spandex fibers is its recovery.

Recovery refers to the ability of the material to go back to the previous shape and size. Elastic recovery is a very important chemical property in textiles and their clothing utilities.

Most fabrics marked as stretchy may only have 1 – 2% spandex fibers in them. These materials will be able to stretch and recover fairly well, but after some wear, wash and use, these fabrics can bag out or sag.

If the spandex % is 4% or more, that means the spandex percentage is that much more, and the performance of the fabric also improves.

Different types of stretch of different spandex fabrics

2-Way Stretch fabrics

These fabrics will stretch across the width of the fabric and the lengthwise direction. Spandex fabrics are generally 2 way stretch.

Stretch satin, and stretch lace are 2 way stretch materials. Stretch Denim fabric is another example.

4-Way stretch fabrics

These are materials that a super stretch capacity in all directions- crosswise and lengthwise. These are the materials best suited to make dancewear, gym wear and other body-fitting garments.

They are heavier than the 2-way stretch materials.

SPANDEX BLENDS – Does more spandex mean more stretch?

Yes, more spandex fibers mean more stretch. 

Usually, the fabric will be marked like this – 95% polyester 5% spandex. This means the fabric is composed of 5% spandex fibers. This will be a moderately stretchy fabric. If the spandex fibers are more than 10% that will be super stretchy fabric.

Good stretchy denim may have >3% Spandex fibers.

The higher percentage of spandex will mean that the fabric will not sag or lose its shape as they stretch out in 2 or 4 different directions, then recover very well to its original size.

Usually, non-elastic fabrics do not have this kind of elastic recovery. They may break if stretched beyond their limit. And even if they stretch, they will not go back to the same size once the stretch is relaxed, leading to unattractive bagginess and sag.

How much does spandex stretch – How to find the stretch percentage of spandex?

Usually, the stretch content of fabric will be listed on the fabric care label. Eg. 50% cotton, 47% rayon, 3% spandex. But that is not the stretch percentage of the fabric. That is the percentage of the spandex fiber in the fabric. 

Stretch capacity is the amount of stretch in a fabric.

If you want to know the correct stretch and recovery of a fabric, you can try this test.

Step 1. Cut out a small piece from the spandex fabric of 2 inch length. Fold the fabric by the middle; hold the doubled fold between your fingers. If you cannot cut down, just mark on either side of a 2 inch length.

Step 2. Stretch the material against a ruler. Stretch the right edge of the fabric with your hand as far as it will go without straining. Measure this stretch. In the picture below the fabric (the length I have marked on the fabric as 2 inches) has stretched to 3.5 inches. 

Step 3.The stretch percentage = Calculate the Second measure minus the First measure. Then divide the answer by the second measure. Then multiply this by 100. You get the stretch percentage.

As the 2 inch fabric has stretched to 3.5inch that is a 42% stretch. If the 2 inch long fabric stretches to 4-inch length, then you have a fabric with a 50% stretch

A fabric with 25% stretch capacity is considered as having minimal stretch. 50% stretch is considered as moderate stretch. More than 75% stretch is considered very stretchy.

Step 4. Do this for all the grain of the material – lengthwise and crosswise. Because these fabrics differ in the way they stretch across and lengthwise.

Check if the fabric stretches only in one way direction or if it stretches two ways – both crosswise and lengthwise.

Some more Frequently asked questions:-