Performance Fabric Terms, Decoded: What the Label Actually Promises

There is one number on a garment label you can rely on completely: the fibre content percentage. Everything printed around it varies from precise to meaningless.

These describe something the fabric genuinely does. There is no minimum standard a garment must hit to use them, but the underlying property is real.

Four-way stretch is the most reliable of these, because it is a structural fact rather than a performance claim: the fabric either stretches both ways or it does not, and elastane content is what delivers it.

These look like specifications and are brand names. Owning one tells you which company made the fabric, not how it performs against anyone else’s.

None of these are wrong or dishonest. They are simply brand names for polyester constructions that all work on the same principle, which is why a garment without one can perform identically.

A short list, but it covers most of what appears in product copy.

• “Performance fabric” — means nothing specific whatsoever.
• “Technical” — describes intent, not construction.
• “Athletic fit” — a cut, and not a standardised one.
• “Premium cotton” — unregulated; ask for the weight.
• “Sweat-proof” — no fabric is.

Where a term is genuinely tested, there is usually a published method behind it. ASTM International publishes many of the textile test methods manufacturers cite, which is a useful reality check when a claim sounds specific but names no standard.

Two completely different things are sold under this heading, and they behave differently over a garment’s life.

A treatment applied to polyester is not the same as a fibre that resists odour inherently. Why synthetics hold smell at all is explained in our gym clothes care guide.

Four things, all of which are on the label or visible in the shop, and all of which tell you more than the marketing does.

Roughly 5 to 12 per cent elastane is the range that gives real stretch with good recovery. Below that, the garment barely moves. Above it, the fabric tends to cling and go slack sooner. Fabric weight and what it means is in our workout t-shirt fabric guide.

This is the practical consequence of the whole distinction. A property built into the fibre lasts as long as the garment. A property applied to the surface does not.

Fabric softener is the clearest example: it makes a garment feel better immediately and coats the fibres that do the wicking. It is the one finish worth actively avoiding.

These follow the same pattern as the performance claims: some are specific and verifiable, some are marketing, and the difference is whether a standard is named.

Bamboo is the clearest example of the gap. The fibre begins as a plant and reaches the garment as regenerated viscose, which is a chemical process. Our bamboo fabric guide covers what that does and does not mean for the finished short.

None of this means the claims are dishonest. A polyester tee marketed as moisture-wicking genuinely does wick, and a fabric sold as four-way stretch genuinely stretches both ways.

The point is narrower: the words tell you which category a fabric is in, not how good it is within that category. Two shirts can carry identical claims and perform very differently, and the label will not tell you which is which.

1. Fibre content is the only regulated number on the label.
2. Dri-FIT and similar are trademarks, not specifications.
3. Four-way stretch is the most reliable descriptive claim.
4. Anti-odour finishes wash out; odour-resistant fibres do not.
5. Check elastane percentage and gsm, not adjectives.

How those fabrics behave once you own them is covered in the care guide, and how they perform in heat specifically is in the hot-weather training guide.