Elastane (spandex) fabric
A polyurethane-based polymer. The fibre stretches 5–8 times its length and springs back. Added at 2–20% to other fibres. In the US it's spandex; the best-known brand is Lycra.
Also called: spandex, Lycra
How it feels
You don't feel it – it adds stretch.
Season: Spring and autumn; next to skin it can feel stuffy in the heat.
What it's used for
Jeans, leggings, swimwear, activewear.
2–3% elastane in jeans gives comfort without bagging; over 5% means skinny jeans and leggings.
Pros
- Comfort and shape retention
Cons
- Heat and chlorine break it down – the garment goes baggy
Care: a typical label
Always follow your own garment's label – blends and finishes change the care.
How it's constructed
Knit. One yarn interlocked in loops – so the fabric stretches sideways and creases less, but can stretch out.
A little history
Elastane was invented in 1958 (DuPont's 'Lycra') and transformed swimwear, sportswear and jeans.
How to recognise it
Synthetics are smooth, often slightly shiny, light and crease-free. They melt as they burn, smell of plastic and leave a hard bead.
Sustainability
Made from oil, don't biodegrade and shed microplastics in the wash. Recycled polyester (rPET) cuts oil use but not microfibre shedding; filter wash bags catch it.
When buying
Synthetics are great for sport, but for next-to-skin wear choose blends with natural or regenerated fibres – they breathe better and hold less odour.
Frequently asked
01What is elastane (spandex)?
A polyurethane-based polymer. The fibre stretches 5–8 times its length and springs back. Added at 2–20% to other fibres. In the US it's spandex; the best-known brand is Lycra.
02Is elastane (spandex) a natural fabric?
No – it's a synthetic fibre made from petroleum.
03Does elastane (spandex) shrink?
No – elastane (spandex) hardly shrinks, unless washed or ironed very hot.
04Is elastane (spandex) breathable?
Only so-so: elastane (spandex) doesn't absorb moisture, it moves it along – fine for sport, less so next to skin on a hot day.