Fibre science
The cabin is a hostile environment for fabric: 5–15% relative humidity, a 20-degree swing between cruise and a hot ramp, twelve hours of static seated load, and UV exposure well above what you get at sea level. Here is what the fibre actually does about each of those.
Body odour is not sweat. It is what bacteria produce after they metabolise sweat on a surface. Polyester is hydrophobic, so sweat sits on the fibre surface where bacteria thrive — which is why a synthetic base layer is unpleasant by hour six and permanently faintly sour after a season.
Merino works differently in two ways. Its keratin structure absorbs moisture into the fibre, away from the surface bacteria need. And keratin chemically binds the volatile acids that carry odour, holding them until a wash releases them. The result is not masking. It is sequestration.
Our 2024 wear panel put twelve line pilots in a single pair across a nine-day pattern. Independent sensory scoring returned no perceptible odour at day nine. We stopped the test there because the pattern ended, not because the garment failed.
Merino fibre has a natural three-dimensional crimp. Crimp creates dead air pockets, and dead air is the best insulator available — which is why the fabric feels warm when the flight deck is cold at FL390.
The same fibre absorbs up to 35% of its dry weight in water vapour without feeling wet, then releases it to the surrounding air. That phase change carries heat away from skin, which is why the same garment does not cook you during a 45-degree turnaround. Cotton absorbs about 25% and simply keeps it, going cold and heavy against you.
Practically: one garment, no layer changes, no mid-sector adjustment. The variable you stop thinking about.
03 — The details that only show up at hour eleven
Dry cabin air makes polyester generate and hold charge — irritating against skin and mildly unhelpful around avionics. Merino's absorbed moisture keeps the fibre mildly conductive, so charge dissipates instead of building. You stop getting zapped by the galley trolley.
The human itch threshold sits near 22 microns — coarser fibres are stiff enough to press on nerve endings. At 17.5µ the fibre bends on contact. That is finer than the standard cashmere threshold and puts our clip in the top 2% of the Australian wool market by fineness.
Pure fine merino is fragile. We spin the wool around a continuous Tencel-nylon filament, so abrasion loads travel through the core rather than the wool. Roughly three times the wear life of 100% merino, with no change to how it feels or how it manages moisture.
Flight-deck UV exposure at cruise altitude is meaningfully higher than at sea level. Merino's protein structure absorbs UV inherently — our fabric tests at UPF 30+ with nothing added and nothing to wash out.
Full specification
| Fibre diameter | 17.5 micron (± 0.4), top 2% of Australian clip |
|---|---|
| Staple length | 70–80 mm |
| Origin | Four family stations, New South Wales tablelands |
| Animal welfare | Certified non-mulesed; Responsible Wool Standard accredited |
| Yarn construction | Core-spun: merino sheath over Tencel-nylon filament |
| Knit | Interlock, 150 / 180 / 195 gsm by garment |
| Moisture regain | Up to 35% of dry weight in vapour |
| Static dissipation | Inherent; no antistatic finish applied |
| UV protection | UPF 30+ inherent, no applied finish |
| Chemical finishes | None. No antimicrobial, no softener, nothing applied to the fibre |
| Certification | OEKO-TEX Standard 100 Class I |
| End of life | Biodegrades in soil within 12 months; no microplastic shed |
| Manufacture | Knitted and sewn in northern Portugal |
At some point you have to fly a rotation in it. Ninety nights, free returns, no explanation required.