The short answer: they are the same fibre
Spandex, elastane and Lycra all describe a synthetic fibre made mostly of segmented polyurethane. The US Federal Trade Commission defines spandex as a fibre of at least 85% segmented polyurethane. The EU defines elastane the same way, adding that when it is stretched to three times its length and released, it recovers quickly to almost its original length.
The fibre was developed at DuPont in the 1950s by the chemist Joseph Shivers, who was looking for a replacement for rubber in clothing. According to the National Inventors Hall of Fame, it could stretch to five times its original length and still recover. DuPont sold it as Lycra, which is still a registered brand name today. "Spandex" became the generic name in North America; "elastane" is the name in the international ISO list, which Europe uses.
How much elastane goes into a garment
Elastane is never used on its own. It is blended with other fibres, often as a core inside a cotton or nylon yarn, or knitted alongside them. The share by weight decides how much the fabric stretches and how firmly it holds.
| Garment | Typical elastane | What it does |
|---|---|---|
| Jeans | 1–2% | Comfort stretch in a rigid-looking denim |
| Fitted t-shirts and rib | 3–5% | Recovery, so necklines and cuffs keep their shape |
| Joggers and fitted sweats | 2–5% | Movement and less bagging at the knee |
| Leggings and sports bras | 15–25% | Compression, shape retention and coverage |
| Swimwear | 15–25% | Close fit that holds when wet |
Heat and chlorine
Elastane is the part of a stretch fabric that wears out first. High heat in the dryer or from an iron weakens it, and chlorine in pool water breaks it down over time, which is why old swimwear goes baggy. For care labels, a cool wash and low or line drying protect it.
For swimwear that will spend hours in chlorinated pools, ask about chlorine-resistant elastane, or a polyester or PBT fabric with less elastane. Our polyester vs nylon guide compares the fibres it is usually blended with.
Which name to put on the label
The fibre content label has to use the fibre names each market allows. Here is what the rules say:
| Market | Accepted name | Notes |
|---|---|---|
| United States | Spandex or elastane | The FTC accepts ISO names such as elastane alongside its own generic names. |
| Canada | Spandex or elastane; in French, spandex or élasthanne | Fibre content must normally be in English and French. |
| United Kingdom | Elastane | The UK keeps the EU list of fibre names. |
| European Union | Elastane, in the local language | For example élasthanne (French), Elasthan (German), elastano (Spanish), elastaan (Dutch). |
| New Zealand | Elastane | Only permitted fibre names can be used: "elastane", not "spandex". |
| Australia | No mandatory fibre label | Any fibre content you state must be accurate. |
So if you sell in more than one of these countries, "elastane" works everywhere, with "élasthanne" added for Canada. Our New Zealand guide, UK guide and Canada guide cover the rest of each country's label rules.
Using the Lycra name and small percentages
- Brand names go next to the generic name. In the US, a trademark such as Lycra must appear next to the generic fibre name, as conspicuous and in the same size, for example "20% Lycra® spandex". The EU and Canada also allow a brand name immediately before or after the fibre name, and Canada does not allow it to be more prominent. Use a brand name only if the fabric really contains that branded fibre.
- Small amounts still count. In the US, fibres under 5% are normally grouped as "other fiber", but one with a clear function at that amount, as stretch is, can be named, for example "96% cotton, 4% spandex". The EU expects every fibre to be listed with its percentage, so list the elastane.
- Percentages have a tolerance. The EU allows a 3% manufacturing tolerance between the stated composition and a lab analysis; Canada allows 5% on blends. Ask for the fabric's composition from the mill rather than estimating it.
| Language | Elastane |
|---|---|
| Italian, Polish, Czech, Slovenian, Swedish | elastan |
| Spanish, Portuguese | elastano |
| Danish | elasthan |
| Finnish | elastaani |
Getting it right in production
Write the full composition into your tech pack, for example "78% nylon, 22% elastane, 260 GSM", along with the markets you sell in. Test the sample the way it will be worn: stretch it, sit and squat in it, wash it, and for leggings check that it does not turn see-through when stretched.
At Nevear the minimum is typically 50 pieces per item, samples take 2–3 weeks, and bulk orders usually arrive 3–4 weeks from the order date, shipping included. The fibre composition is confirmed with the fabric at sampling, so your label can be finalised before bulk.