What is linen? What it is made of, and how it is made

What linen is made of

Linen is made from flax. EU law defines it as fiber obtained from the bast of the flax plant, Linum usitatissimum. Bast fibers are the long, strong strands that run up the stalk between the outer skin and the woody core. US labels name the fiber linen; the word is one of the generic fiber names the Federal Trade Commission lists for fiber content labels.

Linen is one of the oldest textiles there is. Linen samples have been reported in the remains of Swiss lake dwellings about 10,000 years old.

How linen is made

In Europe, flax is sown in March or April and is ready in about 100 days. From July the plants are pulled up by the root rather than cut, which keeps the fiber at full length, and left lying in rows in the field until September. Native fungi loosen the fiber from the rest of the stem while it lies there. That’s called dew retting, and it’s how most of the world’s textile flax is processed.

Once the stalks are dry, they’re scutched, which means beaten to strip off the woody core, and then hackled, or combed until the fibers lie straight. The combed fiber is drawn into ribbons and twisted into yarn, often wet-spun in warm water.

Nothing gets melted or dissolved along the way. The fiber in a linen shirt is the fiber that grew in the stalk.

Linen, cotton and polyester

	Polyester	Cotton	Linen
What it is	Plastic (PET), mostly from fossil fuels	Seed fiber from the cotton boll	Bast fiber from the flax stem
Share of world fiber, 2024	59%	19%	About 0.3%
EU conventional moisture value	1.5%	8.5%	12.0%
Plastic microfibers	Sheds them in every wash and wear	None	None
At the end of its life	Did not appreciably degrade in water tests	Biodegraded in water tests	Biodegrades in soil

The moisture values are the allowances EU law assigns each fiber when calculating fabric weight: 12.0% for linen, 8.5% for cotton and 1.5% for polyester. They reflect how much water each fiber holds under standard conditions.

Where linen comes from

Most of the world’s linen starts in a narrow coastal band of Western Europe. About 70% of the flax grown for fiber in 2024 was grown in Europe, with France the largest producer. The European flax industry puts three-quarters of the world’s long flax fiber in France, Belgium and the Netherlands, and 85% to 90% of Europe’s flax fields in France.

The same industry body says European flax is generally grown without irrigation and with low fertilizer and pesticide inputs, and that the European variety catalogue contains no genetically modified flax. These are the industry’s own statements.

What happens to linen at the end of its life

Flax fiber biodegrades. In soil tests under aerobic conditions, native flax fibers were broken down by microorganisms, and they were also degraded by bacteria in the lab. Polyester is plastic and does not.

How to spot real linen on a label

A US label must list every fiber that makes up 5% or more of the fabric by its generic name and percentage, largest first. Real linen reads 100% linen. A blend lists each fiber, for example 55% linen, 45% cotton. If the label says polyester, the fabric is plastic whatever the product name says.

“Linens” is a different word. Bed linens, table linens and towels are often cotton or polyester; the fiber content label tells you which.