How much stretch to expect in the fabric

Short answer: Pure bamboo viscose stretches a little on its own. Five percent elastane gives noticeable stretch that also pulls back.

Stretch without elastane

Knitted fabric stretches because the stitches can straighten. That is enough to get a garment on but not enough for it to follow the body. Without elastane the stretch also stays, so the garment grows through the day.

What elastane does

Elastane pulls the fabric back into shape. Two percent gives light assistance, five percent gives real stretch, and above ten percent is used only for activewear and socks. See bamboo leggings.

Where you need it

Underwear, leggings, activewear and socks are markedly better with elastane. T-shirts and nightwear do fine without, provided the cut is not close fitting. See bamboo underwear for women.

The price of elastane

Elastane is less durable than cellulose fibres and breaks down with heat. A garment with a lot of elastane therefore needs cool washing and no hot tumbling to last. See bamboo activewear for women.

Frequently asked questions

Can you tell from the fabric whether there is elastane

Often yes. Stretch the fabric across and let go. If it snaps back quickly there is elastane in it.

How much elastane is too much

For everyday clothing, above ten percent is rarely needed and makes the fabric warmer.

Does elastane wear out

Yes. It is usually the elastane and not the bamboo fibre that decides a garment's life.