What Is Elastane? Spandex, Lycra and the Difference

Elastane, Spandex, and Lycra are three names (some of them trademarks) for the same synthetic fiber. This fiber provides stretch and fit to almost every garment that sits close to the body, but it is rarely found alone in fabric: a small percentage is enough. We explain what elastane does, where its weaknesses lie, and which alternative we at erlich textil are already using.

Elastane, Spandex, Lycra: three names, one material

If you read "spandex" on the US label of your favorite leggings and "Elasthan" (elastane) on the German label, both refer to the exact same fiber. Lycra also stands for the same material, but it is a protected brand name, not a separate type of yarn.

Comparing Elastane, Spandex, and Lycra

The short answer to the most frequently asked question: Yes, elastane and spandex are the same material. The difference lies solely in the name and who uses it.

One material, three names. Chemically, all three are polyurethane elastomers, and this very structure explains the fiber's enormous stretchability.

Who invented elastane?

The fiber was created in 1958 in the laboratories of the US chemical company DuPont. Joseph C. Shivers had been tinkering since the early 1950s with a lightweight, stretchy alternative to the rubber threads that were common in form-fitting clothing at the time. His result was a polymer that combined the elasticity of rubber with the comfort of a textile fiber. In 1962, DuPont launched the fiber under the brand name Lycra. The trademark rights were later held by the US company Invista and are now held by The Lycra Company.

Why is it called Spandex instead of Elastane?

The name Spandex is an anagram of the English word "expands." This term has become standard in North America. In Europe and most other regions, "elastane" is the common collective term for the fiber. EU textile labeling exclusively requires the full name, which is "Elasthan" in German and "elastane" in English. Abbreviations like EA are not permitted on EU labels, even if they are common in retail and technical data sheets. Spandex, meanwhile, is the common term for the same material in the US and Canada; it does not appear on EU labels.

What is Lycra?

Lycra is not a separate material, but a brand name. Think of it like "Kleenex" for facial tissues. If you see Lycra on a label, you know that the elastane in your garment comes from Lycra production. There are also other branded elastanes: for example, Creora, Roica, or Dorlastan. Each of these brands produces elastane yarns that may differ in purity, stretch properties, or sustainability profiles.

How is elastane constructed?

Elastane is a synthetic fiber. In detail, it is a polyether-polyurea copolymer consisting of at least 85 percent polyurethane. It sounds complex, but it is important to understand: two building blocks provide the fiber's characteristics.

Polyurethane builds the long, strong molecular chains of the fiber. It provides tensile strength. Polyethylene glycol acts as a soft block between these chains, allowing the fiber to stretch and return to its original shape. This combination is the secret behind its enormous elasticity: elastane can stretch up to 600 percent of its original length without breaking. When stretched less, it returns to its original form every time without sagging.

Unlike rubber, elastane is very lightweight, resistant to skin oils and sweat, and impervious to many chemicals. This is precisely why it has largely replaced rubber threads in the clothing industry.

What elastane does in underwear

There is no such thing as a garment made of 100 percent elastane. The fiber is always mixed with other materials; otherwise, the fabric would be so stretchy that it could not hold any shape. In our underwear, a content of about three to ten percent elastane in the material blend is enough to ensure fit and comfort. For particularly elastic fabrics, the proportion is significantly higher: our Iconic Mesh collection, for instance, uses 21% elastane—more on that in our guide What is mesh?.

You will find typical blends in our range in these variants:

• Modal with elastane: soft, flowing material, high comfort, slight stretch. More on this in the magazine article on modal and on the modal material page.
• Cotton with elastane: tightly knitted, classic cotton feel. Background info in the article on organic cotton.
• Lace with elastane: fine structure with support.

Without elastane, the elastic edges would sag, the bra cup would lose its shape, and briefs would simply slip down.

How sustainable is elastane?

Conventional elastane is not sustainable. This statement is important to us because many brands dance around this point. The reality: elastane is made from fossil raw materials, production is energy-intensive, and the fiber is barely recyclable at the end of its product life. Once processed in a material blend with cotton or modal, it cannot currently be cleanly separated from the other fibers.

Then there is the issue of microplastics. Like all synthetic fibers, elastane can release microscopic fiber particles into wastewater during washing. The proportion is small compared to pure synthetic fabrics like polyester because elastane only makes up a small part of the material blend. Still, it is not negligible.

Our position is clear: we keep the elastane content in our products as low as possible because a little stretch is necessary for the fit. In selected collections, we therefore use the stretch yarn ROICA™ V550.

ROICA™ V550: the elastane alternative we use

ROICA™ V550 is a stretch yarn from the Japanese fiber manufacturer Asahi Kasei. It replaces conventional elastane in the material blend. At erlich textil, we use Roica V550 in selected collections where elastane stretch is required.

You can identify what distinguishes ROICA™ V550 from standard elastane based on two concrete points:

1. Cradle to Cradle Material Health Gold according to Asahi Kasei. ROICA™ V550 has achieved a Cradle to Cradle Certified® Material Health Gold Level. This certificate evaluates whether a material is made from chemically safe ingredients. Important: The award applies to the yarn itself, not automatically to the finished garment.

2. Partial degradation only under industrial composting conditions. According to Asahi Kasei, the elastane Roica™ V550 partially degrades in lab tests (ISO 14855) under industrial composting conditions: 29.9% in 180 days. This does not happen in nature or in household trash. It therefore does not meet the threshold for "biodegradable." It is not, however, a free pass for careless consumption.

More background on the fiber and our use of it can be found on our ROICA™ material page.

Caring for elastane properly

Elastane is sensitive to temperature. If you want to keep your items for a long time, you should pay attention to a few things when washing and drying.

• Wash at a maximum of 40 °C on a delicate cycle. Higher temperatures break down the polymer structure, and the garment loses its elasticity. This also applies to high temperatures in the dryer, so it is best to air dry.
• Do not use fabric softener. It forms a film around the fiber and reduces elasticity. If you need something to combat limescale in the water, a small splash of clear vinegar in the fabric softener compartment does the same job.
• Dry flat instead of hanging. Wet material is heavy, and its own weight pulls the elastane threads out of shape. Clothespins leave pressure marks that cannot be smoothed out.
• Use a low temperature when ironing. Usually, ironing is unnecessary because elastane blends hardly wrinkle at all.

If your specific piece requires different care (for example, because of lace or a special coating), check the care label. That always takes priority.

Frequently asked questions about elastane

Is elastane the same as spandex?

Yes. Elastane and spandex refer to exactly the same synthetic fiber. "Spandex" is the term commonly used in North America, while "elastane" is the mandatory name in the EU. Lycra is additionally the brand name of a specific elastane manufacturer.

How much elastane is typically in underwear?

In high-quality underwear, the elastane content is usually between three and ten percent. More is rarely necessary and often leads to a "rubbery" feel. Less than two percent is often not enough for stable waistbands and a shape-retaining fit.

Can you make clothing out of 100 percent elastane?

No. Pure elastane would be so extremely stretchy that the garment could not hold its shape. The fiber is therefore always mixed with other materials such as cotton, modal, lyocell, or polyamide.

Is elastane harmful to the skin?

On healthy skin, elastane is generally well tolerated. Real elastane allergies are rarely documented. Irritations are usually caused more by dyes, finishing chemicals, or trapped sweat in tight-fitting synthetic clothing. If you have sensitive skin, a high natural fiber content with only a little elastane is a good choice. You can find tips on this in the magazine article on underwear for sensitive skin.

What is the difference between elastane and Roica?

ROICA™ is a brand family for stretch yarns from the manufacturer Asahi Kasei. The variant ROICA™ V550 is an elastane yarn that, according to Asahi Kasei, has received the Cradle to Cradle Certified® Material Health Gold Level (applies to the yarn, not the finished product). According to Asahi Kasei, the elastane Roica™ V550 partially degrades in lab tests (ISO 14855) under industrial composting conditions: 29.9% in 180 days. This does not happen in nature or in household trash. It therefore does not meet the threshold for "biodegradable." Technically, it belongs to the elastane family and is chemically related to classic spandex, but it behaves differently in production and at the end of the product's life.

How do you wash clothing with elastane?

At a maximum of 40 °C on a delicate cycle, without fabric softener, and drying flat. Higher temperatures, tumble dryers, and clothespins significantly shorten the life of the fiber. If the care label of your garment recommends something else, follow the label.

What is elastane made of?

Elastane is a synthetic polymer, more specifically a polyether-polyurea copolymer with a polyurethane content of at least 85 percent. The solid polyurethane chains give the fiber tensile strength, while soft segments in between allow it to stretch and return to its original shape. The raw material basis consists of fossil feedstocks: elastane is created in a chemical plant, not in a field or from an animal.

Is elastane a plastic?

Yes. Elastane is a synthetic polymer based on polyurethane and is therefore a plastic made from fossil raw materials. It is neither a natural fiber nor a cellulose fiber like modal or lyocell. That is precisely why we keep the content as low as possible and, where possible, rely on the stretch yarn ROICA™ V550.

Elastane or Elastan: which spelling is correct?

In German, "Elasthan" is the correct spelling, and in EU textile labeling, this full term is exclusively required. Abbreviations like EA are not permitted on EU labels, even if they are common in retail and technical data sheets. "Elastan" without an 'h' is the Scandinavian variant, while the fiber is called "elastane" in English. Spellings like elastine, elastene, or elastaine appear in search queries constantly, but they all refer to the same fiber.

Sources

• Asahi Kasei: ROICA™ V550 product data sheet and certification details.
• Cradle to Cradle Products Innovation Institute: public entry for ROICA™ V550 Japan BN.
• ISO 14855-1: Standard for the determination of the ultimate aerobic biodegradability of plastic materials under controlled composting conditions.
• erlich textil: material pages for Elastane and ROICA™.