A Potted History of Waterproof-Breathables

With the release of HydroFoil™ Endure, Fraser squints in the rearview mirror to track the evolution of waterproof-breathable fabric technology over the past fifty years to this new high-water mark.

Like many good things, the original Gore-Tex was the result of a happy accident. While messing around stretching PTFE (teflon) they created a membrane with tiny holes that were just the right Goldilocks size to be both waterproof and breathable – small enough to block water molecules (ie. rain) but big enough to let water vapour (ie. sweat) escape. Wikipedia reveals the first waterproof-breathable rain jackets hit the market in the late 1970’s.

Early Winters jacket.

I’m unsure when the technology made the long trip to NZ. Import restrictions and licensing arrangements air-gapped us from the rest of the world back then. But as a uni student and keen tramper and cyclist in the 1980s I recall coveting a Gore-Tex anorak made by Macpac Wilderness Equipment. It was touted as a huge step forward from the then regulation PVC or dry japara jackets. The early variations had issues with delamination and leaking. Not everyone was a convert.

Fraser cycle touring.

The tech improved a lot over the next few decades. Gore-Tex was joined by other manufacturers using PU (polyurethane) membranes. The membrane became more waterproof, more breathable and more durable. A laminated internal tricot (knitted) mesh lining was added to protect the membrane. Tape sealing covered the seams and needle holes.

At Ground Effect we introduced our first waterproof-breathable jacket, the Flash Gordon, in 1997. It was made from a then new Gore fabric called Activent. Highly breathable and lightweight, it was one of the first fabrics suitable for high aerobic activities like cycling and running where you obviously sweat a lot more than tramping or skiing.

Curiously when you get wet while wearing your rain jacket, it’s most often not because it is leaking but because it has become overloaded with sweat. Even if you don’t think you’re sweating, you do continually transpire. That moisture vapour wants to escape and if/when it can’t, it condenses and settles on your inner clothing and skin. Even the most breathable fabrics can’t always keep up your workload, and their breathability is compromised when outer fabric becomes saturated. And because waterproof-breathable fabrics are also windproof, you miss out on the cooling effect of a nice breeze as you ride along (hence why some of our garments have zips or ‘mechanical venting’).

Whilst improving the performance of the waterproof-breathable membrane, fabric suppliers also worked on the other key performance variable: water repellency.

The outer fabric was treated with a water repellent chemical that caused water to bead up and roll off, extending the time that it would remain dry before wetting out. This is important because wet fabric does not breathe at all – rendering the expensive breathable membrane to be ineffective.

Early versions were quite effective, as in long lasting. The acronym DWR (Durable Water Repellency ) was coined. Sadly they relied on long chain carbon C8 molecules, which we now know to be quite nasty. They were banned around 2015 and replaced by shorter chain C6 treatments.

C6 works ok, but is not as durable. DWR was no longer an accurate name. An after-market spray like TX Direct was needed to be reapplied to rainwear quite regularly after washing to restore its water repellency.

For some years the outdoor apparel industry has been hunting for an advance on C6. This became more urgent as many countries moved to ban C6 as it belongs to the PFAS group of forever chemicals. Fabric manufacturers began moving to C0 (Carbon 0) treatments. No PFAS, but based on our testing also not that effective in repelling water. Certainly it is not durable.

About 18 months ago we started testing a new fabric from our supplier Pertex in Japan. It featured a PFAS-free silicone-impregnated repellant. This is not new technology – tents and some water resistant jackets have used it to great effect for a number of years. But until now, it wasn’t compatible with the lamination process that binds the outer fabric and membrane together.

Then, the clever boffins at Pertex announced they had nutted that a solution to that. We started testing the new fabric with equal measures of enthusiasm and scepticism.

Our field testing programme generally involves half and half prototypes. In this case the new Hydrofoil™ Endure on one side and the C0 variation on the other.

Endure’s superior performance was obvious even on the first ride, before washing. For the next 12 months Ground Effect staff and Revolutionaries rode and generally abused the garments. Washing them a lot between outings. To our delight and incredulity the Endure maintained its water repellency, and therefore its breathability over time.

Which brings us to today and the release of HydroFoil™ Endure. Any waterproof-breathable garment is an expensive investment, so here’s HydroFoil™ Endure’s advantages over both traditional DWR and the alternative C0 treatments commonly used by other brands:

• Just like our existing HydroFoil™, the Pertex® Shield+ membrane is sandwiched between an outer fabric and tricot lining. The laminate is highly waterproof (20,000mm hydrostatic head) and highly breathable (18,000 gm per sq.m per 24hr).
• The outer fabric has a unique, PFAS-free, silicone-impregnated water repellent treatment. Individual fibres are wrapped with silicone, creating an integrated barrier that is not easily worn off or washed out.
• This lets you wash your rainwear often – without the need to reproof or recharge in a clothes dryer. Keeping your garment clean is critical to maintain performance and extend its life.
• Wet fabrics severely inhibit breathability. Compared with standard DWR and C0 finishes, HydroFoil™ Endure stays dryer for longer in the rain, so your garment maintains its high level of breathability during each ride and over time.

Pedal on

Fraser

Ground Effect Product Design
June 2026