Waterproof gear is becoming ever more waterproof, and the ability of membranes to ‘breathe’ is increasing. 

Gore-Tex. For the past few decades this waterproofing membrane has been an industry yardstick, and for many trampers, nothing else will suffice.

What Gore-Tex does is well known, but what exactly is it? And is it truly the only option ‘guaranteed to keep you dry’, as the membrane’s promotions so famously state?

Gore-Tex owes its existence to Bob Gore, who developed a microporous membrane by expanding polytetrafluoroethylene (commonly known as Teflon). This membrane – referred to as ePTFE – was weatherproof, breathable, thin and flexible. It was ideal for weatherproof clothing and has been available in jackets and other garments since the 1970s.

Gore-Tex was a breakthrough development and for a long time it ruled the roost, but now several other microporous membranes exist: eVent, Entrant, Pertex, plus those developed by outdoor clothing brands themselves. Kathmandu has ‘ngx’, Patagonia has ‘H2No’, The North Face has ‘FUTURELIGHT’ and ‘DryVent’, and Montane has ‘PETRICHOR’ – and that’s not all of them.

Yet Gore-Tex still dominates. Waterproof membranes might have similar design principles, but there are differences between individual membranes that result in varying waterproof ratings (aka hydrostatic head ratings) and breathability ratings. 

Different Gore-Tex products, such as Gore-Tex Paclite Plus for breathability and low weight, or Gore-Tex Pro for durability, have enabled the brand to remain a top performer, and jackets that use Gore-Tex usually carry a higher price tag than those using another proprietary membrane.

That said, the playing field is more even now. Perhaps ‘varied’ is a better description, as brands continue to develop their technologies, particularly as the demand for more environmentally friendly fabrics grows. 

For the past few years I have worked overseas testing outdoor gear from dozens of brands from around the world. My experience has shown that the phasing out of toxic chemicals in outdoor gear (primarily PFAS) has jump-started a frenzy of industry innovation.

Technologies and fabrics used in outdoor clothing had barely changed for decades, but about ten years ago the environmental harm caused by the outdoor industry became a mainstream concern.

Along with the elimination of PFAS and an increasing use of recycled materials, a primary focus for new and developing waterproof membranes has been breathability. As any tramper knows, waterproof jackets have been breathable for a long time but it’s also very easy to reach their limits.

Take Montane’s PETRICHOR. Released in 2024, Montane says breathability was the essence behind its development because achieving a decent hydrostatic head rating isn’t hard but keeping that waterproof fabric breathable is. 

Where most membranes are hydrophobic (they repel water), Martin Walker at Further Faster (Montane’s NZ distributor) tells us that PETRICHOR is hydrophilic (it attracts water). That may seem counterproductive for a waterproof membrane, but by being hydrophilic, PETRICHOR can move moisture and sweat away from the wearer quite efficiently. 

This means that PETRICHOR doesn’t have to be porous (it isn’t). Other waterproof membranes like Gore-Tex are porous because they’re hydrophobic – the pores enable moisture vapour to escape. 

PETRICHOR is just one of many waterproof technologies that focuses on moving moisture away from your body. Polartec Power Shield Pro and Páramo’s Nikwax Analogy have been doing so since the 1980s. 

In light of the sustainability concerns of ePTFE and PFAS, Gore-Tex has developed another membrane technology called ePE. It’s thinner than ePTFE and carries the same top-end hydrostatic head ratings, and it does away with PFAS and has a lower carbon footprint.

Right now the outdoor industry is more active in product innovation and development than it has been for a long time. We’re in an experimental era that will have successes and failures; ultimately, however, outdoor gear will be improved both in terms of performance and environmental impact, and that’s something we can all be excited about.