There is a moment in late spring when linen reappears in wardrobes across the country, and with it the annual mystery of why one linen shirt feels like a cool breeze while another, apparently identical, hangs heavy and stifling. The answer is almost always weight. Getting it right is the difference between a garment you live in from May to September and one that stays on the hanger.

Why Weight Matters More Than You Might Think

Linen is prized for its ability to move air and moisture away from the skin, but that ability is only as good as the fabric's construction. A heavier linen has more fibre packed into every square centimetre, which means less space for air to travel and less breathability in still, humid weather. A lighter linen lets the breeze through beautifully, but may cling, drape thinly, and wear out faster at the seams. Weight also affects how a garment falls: light linens skim and flutter, midweights hold a soft shape, and heavy linens stand away from the body with real structure. Understanding those differences lets you choose with intention rather than guesswork.

Understanding the Numbers: GSM, Weave and Yarn

Linen is usually sold by weight in grams per square metre (gsm), and occasionally in ounces per square yard. Roughly speaking, 100 gsm is very light and 300 gsm is very heavy, with most summer clothing sitting between 120 and 220 gsm. Weight alone doesn't tell the whole story, though. Weave and yarn matter just as much:

• Plain weave — the classic criss-cross structure, airy and crisp, ideal for shirts and lightweight dresses.
• Twill and herringbone — denser, with a subtle diagonal or zigzag pattern, better for trousers and structured pieces.
• Yarn and count — fine, tightly spun yarns create a smoother, denser cloth, while slubby yarns give texture and a more relaxed, rustic handle.

A loosely woven 170 gsm linen will often breathe better than a tightly woven 140 gsm one, so treat the number as a starting point, not a verdict.

Lightweight Linens: 100 to 150 gsm

This is handkerchief-weight linen, sometimes called voile or cambric at the very lightest end. It is made for heat: holiday shirts, kaftans, loose blouses, breezy dresses and scarves. It dries in minutes, packs down to nothing and feels almost cool to the touch.

The trade-offs are real. Pale colours can be semi-transparent, so you may want a lining or a second layer. Edges fray readily, seams need proper finishing, and the fabric can wear thin with heavy use. Because it creases softly rather than sharply, it tends to look relaxed rather than rumpled — a forgiving quality on a long, hot day. For a typical British summer, 130 to 150 gsm is usually the sweet spot; anything below that is best reserved for a genuine heatwave or a trip abroad.

Midweight Linens: 150 to 200 gsm

If you buy only one linen garment, buy it here. This is the weight most shirts, dresses, tunics and lighter trousers are cut from, and it balances breathability with substance. It is opaque in all but the palest shades, holds a gentle drape, softens beautifully with every wash and lasts for years without looking tired.

For British weather, 165 to 185 gsm is remarkably versatile. It copes with a warm afternoon, layers comfortably under a light jacket in the evening, and looks smart enough for the office when pressed. It creases, of course — linen always does — but midweight creases read as character rather than chaos.

Heavier Linens: 200 gsm and Above

Above 200 gsm, linen becomes a different creature. At 220 to 280 gsm it is sturdy enough for trousers, overshirts, pinafores, jackets, aprons and even light outerwear. It stands away from the body, resists a breeze, holds a sharp fold and ages into something approaching heirloom quality.

What it is not is cool in the heat. A 250 gsm linen trouser is wonderful on a blustery coastal evening or a cool June morning, but at 30°C you will feel every gram. If you run warm, stay below 230 gsm for anything you plan to wear in high summer.

Matching Weight to Garment and Occasion

As a practical starting point, these ranges serve most wardrobes well:

• Shirts and blouses: 130–165 gsm
• Dresses and tunics: 140–180 gsm
• Trousers and shorts: 180–230 gsm
• Overshirts and lightweight jackets: 220–280 gsm
• Beach cover-ups and scarves: 100–140 gsm

It is also worth exploring linen's natural-fibre companions. Hemp behaves similarly but is stronger and slightly crisper; ramie has a lustrous sheen and resists creasing a little better; cotton softens the handle and reduces wrinkling; and lyocell, made from wood pulp, adds fluid drape without losing breathability. A linen-cotton or linen-hemp blend can be a sensible compromise if you want the look of linen with less upkeep. Finally, remember that cut and colour count: a loose silhouette in a pale shade will always feel cooler than a fitted garment in a dark one, whatever the label says.