Beyond Polyester: A Fabric Guide for Yoga and Training

Fabric composition is written on the care label in a format that seems designed to be uninformative. 86% polyester, 14% elastane tells you almost nothing about whether a legging will run, hold its shape, or feel good in heat. Here is what those percentages actually mean in practice.

Polyester: the workhorse

Polyester is in almost every performance knit because it handles abrasion, holds colour, and dries quickly. Its reputation comes from low-end fabric, not from the fibre itself. Polyester is hydrophobic, which means it does not absorb sweat but moves it to the surface where it evaporates, and it retains its shape well if the construction is good.

The polyester problem is pilling, and pilling is a construction problem rather than a fibre problem. A well-twisted yarn resists abrasion. A loosely-twisted one pills at the inner thigh in about six weeks.

Nylon: stronger, cooler, smoother

Nylon is roughly 20 percent stronger than polyester by weight and has a noticeably smoother hand. It abrades more slowly, which is why nylon-blend leggings typically outlast polyester ones. Nylon is also slightly more breathable, though the difference in a studio setting is small enough that it rarely decides anything.

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Elastane, and why 14 percent matters

Elastane (also labelled spandex or lycra) is what makes a fabric stretch. The number to look at is not the elastane percentage but the recovery: how much of the original shape comes back after stretching. High-recovery elastane is what stops a waistband from going slack after a year of wear.

A fabric with more than 20 percent elastane can feel unstable in a squat or a lunge, because it has less structural yarn to pull against. Most well-made performance knits land between 12 and 18 percent.

Recycled content

Recycled polyester (often labelled rPET) has essentially the same performance characteristics as virgin polyester. It is chemically the same polymer, and you cannot tell them apart by touch. What differs is the feedstock: rPET uses post-consumer bottles rather than virgin petroleum.

Be sceptical of specific percentages without a certification number. We favour recycled content where it does not cost performance, but we would rather state a modest verified figure than a large unverified one.

What to check before you buy for fabric guide beyond polyester

Two pieces can look identical on the hanger and behave differently in fabric guide beyond polyester. The checks below are the ones that catch it early. Light Provence Blue Ribbed Adore Tank is the piece we would test them against first.

• Reach overhead: the armhole should not pull the hem up with it.
• Side bend in a mirror — a low cut gaps, a high cut restricts the shoulder.
• The hem should stay put in a forward fold without constant tugging.

How to read a label quickly

• Primary fibre (the first percentage) tells you the fabric family: polyester or nylon.
• Elastane between 12 and 18 percent is the sweet spot for a legging.
• Weight in gsm tells you climate suitability more than any fibre name.
• Flatlock or bonded seams are worth more than any single fibre percentage.

Nobody has ever bought a better yoga practice by reading the fibre label. But a poor one ruins it.