To stay dry in the hills, walkers need not only great clothing design but also a great fabric. The Precip is a well-established lightweight jacket but this year Marmot has introduced a new fabric to its range called NanoPro, claiming it is 43 per cent more breathable than the brand’s previous coated fabric. This could make the Marmot Precip the must-have jacket of the year, and with a price tag of just £85 it demands a closer look.
NanoPro is a microporous material, with tiny holes small enough to prevent rain from coming through but large enough to allow water vapour out, so there is no build-up of condensation on the inside. In the lab it has breathability figures of 17,000g/sq m/24 hours, which puts it up there with the best on the market. There’s also a NanoPro Membrain fabric available that is even more breathable with figures of 47,000g/m2/24 hours and this is being used on the Marmot Artemis jacket, which is priced at £200.
Both fabrics can withstand the pressure of a 10 metre high water column, which is lower than other high-end fabrics, which often can withstand a 20 metre water column. However, in reality it can be argued that a jacket that is durably waterproof to 10 metres throughout its life is more than waterproof enough for hillwalking; indeed, it is well above the 1 metre British Standard for a jacket to be called waterproof. The fact here is that the more waterproof you make a fabric, the less breathable it may become, and so to stay dry in the hills walkers need to find a balance between breathability and waterproofness.
NanoPro and NanoPro MemBrain are both 2.5 layer fabrics. This means they don’t have a full scrim on the inside to soak up any condensation, so if condensation does form it is going to be visible and the jacket will feel a little clammy in those situations.
Lab testing is all very useful, but what really matters is how a jacket performs on the hill in a wide range of temperatures. I’ve been using a NanoPro jacket since summer 2013 and I have been amazed at the ability of the fabric to manage condensation. It’s certainly the best 2.5 layer fabric I’ve used, with barely any condensation developing in the summer weather of the Lake District. As the temperature cooled during autumn and winter, the performance hasn’t been quite so good, although it still outperforms any 2.5 layer fabric I’ve used. I have managed to get some condensation build-up though, and on those days a 3-layer fabric with a scrim on the inside would feel drier and more comfortable – but such a jacket would also cost twice as much and probably weigh far more too.
So what this boils down to is that NanoPro is a great fabric. Here it is being used on the Precip, which now benefits from a wired peak on the hood and it also has good large pockets that can be accessed reasonably well while wearing a rucksack. Pit zips are provided, which hints that Marmot realises ventilation is still important if you want to stay comfortable. At £85 the Marmot Precip in NanoPro fabric is a bargain when you consider its breathability performance.
Material NanoPro 2.5 layer
Men’s sizes S-XXL
Women’s sizes 8-16
Weight 320g (size M)
NanoPro is probably the most important development in waterproof jacket technology in the last 12 months, and when combined with the great Marmot Precip jacket design and a superb price for the performance, this could be the best buy of the year.
Review by Graham Thompson
First published in Trail magazine March 2014