Why 5% elastane can be useful

Elastane (also sold as spandex or Lycra) is almost never worn on its own — it is blended in small percentages with a main fibre to add stretch and shape recovery. Reading a composition line as "95% cotton, 5% elastane" tells you something specific and useful, once you know what that 5% is doing.

What a small percentage buys you

At around 2-8%, elastane gives a garment recovery: the fabric stretches with movement and returns to its original shape afterward, instead of bagging out at the knees or elbows over a day of wear. This matters most in fitted garments — underwear waistbands, leggings, fitted t-shirts — where the main fibre alone would stretch and stay stretched. The elastane is a small structural addition, not the fabric's dominant character; a 95/5 cotton-elastane blend still breathes and feels like cotton, just with better shape retention.

What a large percentage costs you

Elastane itself has low breathability and does not absorb moisture the way cotton or wool does. As its share climbs — the very stretchy fabrics used in some compression and swimwear pieces can run 15-20% elastane or higher — the garment breathes less overall and the base fibre's moisture-handling properties matter less because there is simply less of that fibre present. Elastane also tends to be the first component to degrade with heat and repeated washing, which is why high-elastane garments often lose stretch and shape faster than low-elastane ones, regardless of how the main fibre held up.

The trade-off, stated plainly

There is no "right" elastane percentage in the abstract — a small share is a reasonable trade for recovery in a fitted basic; a bare cotton or linen garment with zero elastane will breathe better but may lose its shape faster in a snug cut. What matters is knowing which trade you are making, which is why we show the exact percentage rather than folding it into a vague "stretch cotton" description.

What to look for

• The exact percentage, not just "stretch fabric" or "with a hint of elastane."
• Whether the garment's fit relies on a snug cut (where elastane earns its place) or a loose cut (where it may be unnecessary).
• Care instructions — elastane is more heat-sensitive than most main fibres, and high heat in washing or drying shortens its useful life faster than it shortens the life of the fibre it is blended with.