If you don’t know what it is you’ve probably seen it on your or other trail/ultra runners clothing. In the pursuit of going lighter, Pertex is a family of UK developed materials, used by many trail running and wider outdoor brands of choice in the development of their wind-shells, hard-shells and insulation garments.
Outside of being lightweight, it’s also highly packable and we all know how despite buying 3-20 litre packs, we want the contents to be the size of an apple or smaller, taking up minimal space and allowing us to find an ever greater number of “what ifs” to fill it up.
So, to clarify, Pertex are a series of yarns and membranes, with a variety of unique properties, whether they shed water, resist wind or prevent insulation from leaving the garment.
In an age of far east sourced materials, Pertex has genuine British heritage and harks back to an era of development, as many mountaineers pioneered the modern outdoor world, both in world firsts and technology.
Back in the 80’s Hamish Hamilton, a British climber and mountaineer discovered that moisture would move along the microscopic capillaries of a tightly woven fabric, spreading over a large surface area where it quickly dried. As we can all testify, we’ve all learnt the hard way, what works as a waterproof when the sky dumps it, and you’re left shivering on a fellside, seeking shelter from the howling wind, wishing you’d either packed better, dressed appropriately or looked after that bit of kit.
In the Eighties, Hamish took his idea to Perseverance Mills Ltd., a Lancashire textile manufacturer specialising in very tightly woven synthetic fabrics for use in dot matrix printers. These fabrics relied upon the movement of liquids, in this case ink, along the capillaries of a fabric.
In addition to the printer fabric, Perseverance Mills Ltd., was a leading manufacturer of parachute canopy fabric (the military operate in all climates and weathers, expecting consistency especially when jumping out of planes). The development of canopies led them to expertise in heat calendaring – a technique that allows precise control over the airflow through fabrics.
By combining this expertise with Hamish’s concept of a fabric for outdoor apparel and equipment, the Pertex brand was born.
Pertex fabrics are developed to match the specific needs of the end-user. By altering the design, construction and finish, fabrics can be engineered and tailored to a range of applications and to give the perfect balance of strength, weight, flexibility and softness.
There is no point giving a runner a heavy duty, 3 layer fabric with outstanding waterproofing and minimal breathability, when they plan to run and require to exert and disperse heat and water vapour. Similarly, an ultralight weight wind-shell in the middle of a prolonged Scottish storm, has little use outside of trying to combat the wind.
Therefore, Pertex have a series of fabrics which provides the user the ability to fine tune their decision based on their intended use. And, as I’ve heard it raised in several ultra running seminars of late, going lighter isn’t always better. Getting the correct product to match the weather conditions and being able to operate to their optimum, really does make the difference between a pleasant and miserable experience, race or DNF and at the extreme end of the spectrum, life or death.
For 2017, brands have worked with Pertex on a range of new waterproofs, constructed from Pertex Shield+.
In their own words:
“Pertex Shield+ is the ultimate lightweight, waterproof fabric for fast moving outdoor activities. It uses a hydrophilic PU membrane to provide a high level of dynamic breathability – the harder you work the greater the breathability of the fabric.”
Key Features:
- Provides dynamic breathability
- Very lightweight and packable
- Soft to the touch
- High performance durable water repellent finish
In the summer months, running jackets are perfect. They are incredibly light, packable and breathable. The reality is, for most races, runs and adventures, we don’t plan on using them, as often the weather is fine and it may be hotter to wear one, then run without. However, for seasons with variable weather, winter and when venturing into the mountains, having something with a longer drop tail, larger hood and potentially another layer (i.e. a 3 layer jacket over 2) can vastly improve your running experience. Look at kit used in the Tor Des Geants and Spine Race compared to Marathon Des Sables and Lakeland 100. All may require a waterproof jacket with taped seams, but all have very different operating conditions and likeliness of being used (take MDS with a pinch of salt……ok sand).
Furthermore, for training situations or personal projects, hybrids are proving to offer a great blend of protection and insulation for those who run cold. Being able to start a run with some insulation, but also breathability, which can later be removed and used either for a break, straight away after getting off the trail or an emergency back up in colder weather, reduces the need for two garments in your bag. However, this does not remove the need for proper insulation and weather protection in the mountains, so a considered judgement is necessary.
Below are a selection of jackets being released in 2017, using Pertex Sheild+. This list isn’t everything, so it’s worth looking at your preferred brands to see what they are bringing out. You will also notice, not all are running jackets, but for the reasons stated above, this can sometimes be an advantage in specific situations.
Outdoor Research
Helium Hybrid Hooded Jacket
Ideal for moving fast and light in inclement weather, the Helium Hybrid Hooded Jacket places ultra-lightweight waterproof fabric everywhere needed for weather protection, and then maps in stretchy, breathable softshell fabric in areas less exposed to the elements. It uses Lightweight Pertex Shield+ in the hood, shoulders, upper arms, front and back. Stretchy soft-shell Ferrosi fabric adds freedom of movement and breathability in the sides and under the arms. The result is pit-zip breathability without the zippers, as well as movement mirroring stretch.
Rab:
Arc Jacket
Stretch waterproof jacket using Pertex Shield+ 3 Layer. Pared-back features make this piece the ideal packable and lightweight jacket for year-round active use.
Downpour Jacket
Lightweight, packable and waterproof jacket with pit zips using Pertex Shield+ 2.5 Layer with Dry Touch.
Montane:
Minimus Stretch Jacket
Ultra-lightweight, stretchy rain shell ‘from the future’ is primed for mountain hiking, backpacking and trail running. Fully waterproof Pertex Shield+ 2.5 Layer fabric is exceptionally breathable, allowing sweat to evaporate. A special stretch PU laminate with internal ‘mesh’ print paired with a machine stretched nylon face fabric provides an excellent two-way stretch for added comfort and ease of movement during fast mountain activities. Athletic tailoring engineered for high reach, forward motion activities.
Fusion Alpha Jacket
Unique hybrid jacket combines windproof CS10 fabric with breathable fabrics and insulation for alpine climbing and other high output activities. Zoned hybrid construction was developed using thermal imaging data produced during activities in cold, wet conditions. Pertex Quantum CS10 is used in core body panels and over the shoulders to protect against abrasion, wind and light rain. The core of the jacket is filled with Polartec Alpha synthetic insulation that is fast drying, lightweight and regulates internal temperatures. Additionally, Polartec Power Grid fabric is used on the side of the body, across the back, and in the hood and forearms for superior wicking, freedom of movement and a close, athletic fit.
To find out more about Pertex click HERE
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James Mackeddie 