We’ve spent the last 2 years in R&D building Version 2 of our 100 Year Pants. Designed to combat everything the next century might throw at them – from wildfires to wild weather – we’ve made them lighter, stronger, and stretchier. Built with a Swiss supermaterial developed by Schoeller for the elite military, they’re also highly durable against rips and abrasion. At the same time we’ve completely overhauled the design so they’ll blend in anywhere.

Every pair of 100 Year Pants is built with an ultra technical blend of five high performance materials. There’s an extreme strength nylon ripstop, a polyurethane fire resistant coating, elastane for stretch, a small amount of carbon fibre and nearly 20% aramid, which is the same fibre used to make body armour and bulletproof vests. In a process involving hundreds of separate construction steps, these materials are then assembled into a single, military-grade three-layered fabric.

The outer layer of the pants is a highly abrasion and tear resistant nylon ripstop. When you feel the rugged texture of this layer you get a sense of just how tough and durable it really is. But critically it manages to stay flexible, lightweight and stretchy at the same time. It’s also completely windproof, while remaining breathable to release warm air when you start to heat up. Finally it’s coated with a water repellent treatment that helps the pants resist light rain and snow.

Any contact with flames triggers the middle layer to react. This layer instantly expands to 1000x its size to create a protective barrier between you and the flames, writing off the pants but saving you. It might sound like an airbag, but it looks more like tiny plants growing at high speed as the protective polyurethane coating increases in volume and expands to about 6mm in height. Even if you hold a flame on these pants they can’t catch on fire, and flames simply can’t spread on them.

The final layer next to your skin is made from aramid fibres, which are normally used to make body armour and bulletproof vests. On a weight for weight basis aramid fibres are 5x stronger than steel. They’re also inherently fire resistant. So by adding an aramid layer to the inside of the pants we create another high-strength, flame resistant protective barrier. And we’ve woven the fibres to be soft and smooth, so they feel just as comfortable as a pair of cotton pants would.

High-strength normally comes at the cost of elasticity, but we’ve woven 5% elastane into the 100 Year Pants so they stretch in every direction. The knees come with an articulated construction. And we’ve added a curved panel at the crotch so that whichever way you move you won’t feel restricted. We’ve also reinforced all the critical seams to add strength, including typical failure points like the seat.

To figure out how quickly the material will break down over time we use a test in the lab called the Martindale abrasion resistance. A mechanical thumb rubs the fabric repeatedly until the fibres break. A normal polyester fabric survives 25,000 revolutions. But the 100 Year Pants easily passed 100,000 revolutions – the equivalent of a lifetime’s wear. Even by the end of the test the material still looked brand new.

The pants are equipped with seven pockets to carry all your gear. We’ve built in two large angled pockets at the thighs that are designed to work like traditional cargo pockets, but look far more streamlined. They close with water repellent zippers protected by storm flaps. And you’ll find two more pockets at the back of the pants with the same zippers and storm flaps.

You’ll find two open pockets at either side of the pants, and inside the right pocket there’s a second hidden pocket. It’s fitted with a water repellent zipper so you can securely store valuables inside it. All the pockets are lined with ultratough Cordura to prevent them from wearing out over time.