How to Find Underwear That's Actually 100% Cotton

Look for men's underwear made only from cotton and you'll find it is harder than it should be. Plenty of packs say "cotton" on the front. Far fewer are cotton all the way through. This is a practical guide to telling the difference, so you know what you're buying before it arrives.

Why so little underwear is pure cotton

Most underwear on the high street is a blend. The most common is cotton with around 5% elastane, and much of the rest is made from polyester, nylon or modal. There are reasons for this. A little stretch woven through the whole fabric makes a garment cling to the body, hide a less careful cut and fit a wider range of sizes. Synthetic fibres are also cheap and dry quickly.

The result is that "cotton" has become something brands say about underwear, rather than something it always is. If you want the fabric itself to be cotton, you have to check.

Read the composition, not the packaging

The front of a pack is marketing. The composition is the part that has to be accurate. In the UK, any textile product sold to the public must state its fibre content, and the words "100%", "pure" and "all" can only be used when a product is made entirely of one fibre.

A few phrases are worth knowing:

• "Cotton rich" usually means a little over half cotton, with the rest synthetic.
• "Cotton blend" can mean almost any proportion.
• "Cotton feel" or "cotton touch" describes how something is meant to feel, and often means there is no cotton at all.
• "Organic cotton" tells you how the cotton was grown, not how much of it is in the fabric. An organic cotton pair can still contain elastane.
• "95% cotton, 5% elastane" is the one most people miss. It is mostly cotton, but it is still a synthetic blend.

What you're looking for is a single line: 100% cotton.

Shopping online

Online, the composition is often a click away from the main description. Look for a tab or section called "Details", "Composition", "Fabric" or "Materials". If a product page doesn't give a full breakdown anywhere, it's reasonable to assume it's a blend.

Multipacks need a second look. It isn't unusual for the colours in one pack to be made from different fabrics, and for the listing to show the composition of only one of them. Check that the composition covers every pair in the pack.

Why the waistband is counted separately

You may notice that a pair labelled 100% cotton still has some stretch at the waist. That's normal and it's allowed. Labelling rules don't count an elastic waistband as part of the fabric composition, because it is a separate component rather than the cloth the garment is made from. The same applies to sewing thread and small trims.

A waistband needs a little elastane to stay up. What matters is that the fabric itself, the part against your skin, is cotton. Ours works this way: the fabric is 100% cotton, and the elastane is kept to the waistband, at your waist and away from the most sensitive skin.

What good cotton underwear should feel like

Pure cotton behaves differently to a blend, so it helps to know what to expect. It doesn't cling in the same way, so it depends on a good cut to fit well. Cotton jersey, the knitted fabric used for trunks, has a little natural give. Woven cotton, used for traditional boxer shorts, has none and sits looser. Both should feel soft from the first wear and get softer with washing.

Cotton takes up moisture and lets it evaporate rather than holding it against the skin, which is the main reason people look for it in the first place. We've written more about that in why cotton underwear makes sense for men's health, and about the different fibres you'll find on labels in our plain guide to fabric.

Looking after it

Cotton can shrink a little if it's washed or dried too hot. Washing at 30 to 40°C and drying on a line where you can will keep it the right size for longer. It takes slightly longer to dry than a synthetic blend, which is the trade-off for a fabric that breathes.

Where we stand

We started Gattrell Brown because we wanted underwear made from cotton fabric and found it surprisingly hard to buy. The Original Trunk and The Signature Boxer are both cut from 100% cotton, in white, black, brown and green, and sold as single pairs or in packs of three and five. The composition is the same for every pair and every colour.

Whoever you buy from, it's worth turning the label over. It takes a few seconds, and it's the only reliable way to know what you're wearing.

Fibre names and the use of "100%", "pure" and "all" on labels are set out in the Textile Fibre Names and Labelling Regulation (EU) 1007/2011, which continues to apply in the UK as retained law.