Blends are where labels go wrong

A label that reads "60% cotton, 40% polyester" is making a precise claim. Precision, it turns out, is where labels fall apart.

When EU market-surveillance authorities tested 132 garments across eight countries, blends of natural and man-made fibres failed 64% of the time. The Dutch government-commissioned study that scanned over 10,000 discarded garments found the same weak spot: cotton-polyester blend labels were accurate only about 23% of the time. Read that again. Fewer than one in four.

Why blends? Partly because they're genuinely harder to get right. A garment assembled from yarns bought across a long supply chain accumulates small errors, and nobody re-tests the finished product. But the Dutch data shows something less innocent underneath. About a third of cotton-rich blends claimed much more cotton than they actually contained, and cotton is the fibre shoppers pay a premium for. The errors leaned conveniently in the seller's favour.

There's a control group hiding in the same study. In 11% of cases the expensive fibre was understated, meaning the garment was better than its label said. That's the signature of honest supply-chain error; nobody deliberately undersells their own product. When exaggeration runs at three times the rate of understatement, the gap between those two numbers is the part that isn't an accident.

The practical takeaway is almost boring: single-fibre garments are the safer bet. In the EU campaign, claims of 100% of a single natural fibre failed only 15% of the time. Not perfect. But a label with one number on it gives a manufacturer fewer places to shade the truth, and a tester an easier claim to check.

So when two tops look identical and one says "100% cotton" while the other says "55% cotton, 45% polyester", the blend isn't automatically worse fabric. It's just a claim with worse odds of being true. Buy the blend if you love it. Just weigh the label accordingly.