What Is the Best Fabric for Men's Shorts?
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Most men buy shorts on fit and colour, then find out what the fabric does to them in February.
For a full day in warm weather, merino wool is the best all round fabric for shorts. It pulls sweat into the fibre instead of leaving it on your skin, it does not turn sour after one hot afternoon, and it holds its shape. Linen is better in still, dry heat. Hemp and heavy cotton canvas are for hard physical work. Polyester and nylon dry fastest once fully soaked, which is why they took over swim and race kit, and that speed is the only thing they are giving you.
The number nobody puts in the buying guides
Moisture regain is how much water vapour a fibre takes into itself before its surface feels wet. Wool sits at 18.25%. Polyester sits at 0.4%.
Higher is better, and that gap is most of what people notice when they switch. Wool takes sweat inside the fibre and lets it go slowly as you cool, so the surface against your skin stays dry. Polyester absorbs next to nothing, so the sweat has nowhere to go except your skin and the face of the fabric. It works while air is moving over you. It stops the second you sit down.
Cotton is the awkward middle at 8.5%. It drinks readily, then saturates and holds the water against you, which is the clingy shirt everyone has worn once and remembered. More on that in merino wool vs cotton in hot weather.
The six fabrics, side by side
| Fabric | Moisture into the fibre | Feels dry while you sweat | Dry after a full soaking | Odour after a hot day | Biodegrades |
|---|---|---|---|---|---|
| Merino wool | 18.25% | Excellent | Moderate | Very low | Yes |
| Hemp | 12% | Good | Moderate | Moderate | Yes |
| Linen | 12% | Good in dry heat | Moderate | Moderate | Yes |
| Cotton | 8.5% | Poor once saturated | Slow | Moderate | Yes |
| Nylon | 4% | Fair | Fast | High | No |
| Polyester | 0.4% | Poor | Fastest | Highest | No |
Regain figures from ASTM D1909 and the International Wool Textile Organisation.
Linen and hemp, and where they stop
Linen is superb in still, dry heat. Stiff fibre, open weave, air moves straight through it. It also creases the moment you sit down and has almost no elastic recovery, so linen shorts bag at the knee and seat and stay that way until the next wash.
Hemp is the tougher of the two. Stronger than cotton, similar regain to linen, and it softens as you wear it rather than wearing out. Where it stops is next to skin. Most hemp is coarse enough that you notice, and the smooth versions have been blended back with cotton or viscose.
Neither resists odour the way wool does. Neither is the pair you wear from a coffee to a walk to the water to dinner.
What the synthetics actually buy you
Two facts, said plainly. Polyester and nylon dry faster than any natural fibre once the fabric is fully soaked, and they survive more abrasion in a lab rub test.
Abrasion is the softer of those two claims, because shorts are almost never retired for wearing through. They get retired because the seat has gone shapeless or because you can smell them from the laundry basket. Wool beats polyester on both.
Then there is what is against your skin for eight hours. Polyester repels water but attracts skin oils, so sweat and oil sit in the gaps between fibres, which is the same property that makes them smell. On top of that, synthetic performance fabric usually arrives wearing applied finishes for water repellency and odour control, and PFAS treatments have turned up right across the activewear category. We went through what is actually on those garments in is your activewear toxic. Merino needs none of it. The odour resistance and the temperature regulation are properties of the fibre, not a coating that washes off.
Textile Exchange put global fibre production at 132 million tonnes in 2024, polyester at 59% of it. Synthetic is the default now, and almost nobody wearing it chose it.
What this means for you
Buying one pair to cover most of your life: buy merino, in a tight weave rather than a loose knit. Already own good cotton or linen shorts: keep them for dry days and short outings.
FAQs
What is the best fabric for shorts in hot, humid weather?
Merino wool. It absorbs moisture vapour into the fibre and releases it slowly, so it still feels dry when cotton has saturated and polyester has gone clammy. Linen is the runner up and does better in dry heat than humid, because it relies on evaporation and moving air rather than absorption.
Are linen shorts better than cotton shorts?
For hot weather, usually yes. Linen holds more moisture in the fibre than cotton, around 12% against 8.5%, and the open weave moves air instead of clinging. Cotton wins on price, on softness out of the box, and on surviving any wash cycle.
Do you need synthetic shorts to stay dry?
No. For sweat, which is what you are managing on a normal day, merino keeps you feeling dry longer than any synthetic because it absorbs moisture before the surface feels wet. Synthetics only lead once the fabric is soaked through, which for most people happens a few times a year. The full comparison is in merino wool vs polyester shorts.
Sources
- ASTM D1909, Standard Tables of Commercial Moisture Regains for Textile Fibers
- International Wool Textile Organisation (IWTO), wool fibre performance and commercial regain
- Textile Exchange, Materials Market Report 2025 (2024 production data)
- Callewaert et al. (2014), Microbial Odor Profile of Polyester and Cotton Clothes after a Fitness Session, Applied and Environmental Microbiology
Most shorts are made from plastic. These aren't. See the MARINE|O Merino Wool Walkshort →
Heading into the water specifically? See the MARINE|O Natural Boardshort, built on the same natural-fibre principles as the Walkshort above.