Polyester, Nylon, Cotton? Find Out Which Leggings Are Best for You

(Original article was published on monobclothing.com/blog on May 6, 2019.)

You’ve found the right color, you’ve found the right print, you’ve found the right accent. But what does the fabric content mean?

All (good) leggings must be constructed using an elastic fiber. In most cases, it’s elastane such as spandex. Spandex stretches and hugs every curve of your body. Pure spandex, however, is like a rubber band. It’s sticky, it’s suffocating. But pair it with another fiber like polyester, polyamide (like Nylon), or cotton, and it’s golden.

Breathability

Polyester and polyamide knit fabrics are breathable, although this largely depends on the weave, namely the size and number of holes, and how tightly the fibers are woven together. However, cotton still takes the crown for breathability, although not when it’s wet. Wet cotton is sticky and heavy. Have you ever tried to put on a pair of 100% cotton denim pants when you’re sweating? Yeah, wet and sweaty cotton leggings are probably slightly better than denim pants, but still…

Moisture Management

Let’s face it: we sweat. This is the way our bodies keep cool so we don’t overheat (and die). While polyester is hydrophobic (meaning they’re moisture-wicking and water-resistant), cotton retains water, and this leads to more than just sweat stains. This is why obstacle race guidelines always reminds you to wear polyester-based leggings (and underwear). They dry more quickly than cotton-blend leggings (and underwear). Polyamide threads are not as hydrophobic as hydrophilic (they absorb water, just not as much as cotton), they will feel cold when wet, thus keeping you cool, but it won’t dry as fast as polyester.

Shape Retention

We have four words for you: read the care label.

Try to resist the temptation to just throw in your spandex-blend leggings inside the dryer. Spandex’s strands can dry out and break, causing the item to lose its stretchiness. Polyester and polyamide are still the winners when it comes to durability, but cotton that has been infused with spandex can also hold its shape for a long time, as long as they’re treated with care.

Printability

This is especially relevant for those who’d like to do heat transfer such as vinyl printing on the garment (see Mono B’s Private Label program). Although polyamide-blend, polyester-blend, and cotton-blend fabrics can take heat transfer, polyamide-blend fabrics will melt if the heat is too high. Polyester and cotton can hold printing better than nylon.

Then there’s the prime fabric blend: Supplex® and Lycra®. These two fibers are specially crafted for performance wear. Supplex, a trademark of the brand DuPont, was patented in 1985. Fun fact, DuPont is also the company that invented Nylon, the most famous polyamide, as an alternative to silk stockings. The polymer-based Supplex has finer fibers than regular polyamide, thus making it softer and more water-repellent. Lycra is an elastane. It’s lightweight, almost invisible, and stretches alongside your body during even the most rigorous activities. Our Mono B Bronze line combines Supplex with Lycra to produce pure performance wear. These leggings have stood the test of time, from HIIT sessions to muddy obstacle races.

Ultimately though, activities and temperature will dictate which leggings you need to wear for the day. Although polyester/polyamide (including Supplex) and elastane blend (including spandex and Lycra) are perfect year-round, nothing beats the comfort of lounging in a cotton-blend pair of leggings. And always remember to check the wash instructions to maximize the life of your leggings.

Shop Mono B’s cotton collection (including leggings and athleisure wear):