Monday, 9 August 2010

Montane Prism 2.0 Jacket Review

In the middle of July, Montane sent me a Prism 2.0 jacket to test and review, and to see what I thought of it having just bought the Patagonia Nano Puff. I didn't want to pen even an initial critique until I had time to take it out with me so I agreed with them I'd take it up to the Carneddau for a weekend wild camp and then to the Alps for the TMB. This first analysis deals with the Carneddau and there is another review after 11 days' abuse in the Alps.

I like Montane and, as a clothing manufacturer, they're certainly my preferred choice. However, having recently purchased a Lite Speed and the Nano Puff, I wondered where the Prism would fit in my current set-up. The combination of the Lite Speed & the Nano Puff, with a fleece hat, weighs only a little more (481g) than the Prism (mine is 414g) but gives me more versatility in terms of using either insulating layer and/or windshirt. The Lite Speed works well with my Montane Bionic base layer when I require wind protection (to prevent convective heat loss) but not protection from radiative heat loss (ie an insulating layer). The Prism does both jobs at once which can be useful, for example as a late/early 3 season, colder temperature option, but is potentially restrictive at warmer temperatures. However, the synthesis of primaloft & Pertex microlight is a distinctly breathable marriage so the range in which the Prism will be effective is broad. It obviously breathes better than two garments, as there would be, with two garments, at least another layer of Pertex for perspiration to travel through. It was always going be interesting to see how it performed when I would have used only the Lite Speed and the height & barren flats of the top of the Carneddau would be perfect.

There's no doubting the quality of the Prism. It's extremely well manufactured. Every detail is well-thought out & superbly crafted. I am a 33-34" waist, 20" torso, 39" chest & slightly broad shouldered. The medium fits me perfectly. The athletic cut means 90% range of unrestricted arm movement without the jacket riding up & that last 10%, arms above my head, results in limited movement of the hem, which has a two, one-hand drawcord toggles. Yet this does not make the jacket feel baggy at all. Full marks, therefore, for fit. I initially tried it on without a top & it felt pleasant enough against the skin so arms will likely not suffer from clamminess if a short sleeve base layer is worn. It is 40g primaloft fill with a Pertex microlight shell. Breathable, water resistant, very efficient insulating properties & it packs into one of the pockets to a 20x10x6cm parcel. There is a great post by Section Hiker on the principle of '
compactness' as an extension of lightweight principles that insulating layers, as opposed to fleeces or softshells, fulfil well. Even with a padded, adjustable hood, with velcro adjusters at the back which also help roll the hood away, or to tighten the adjustment, this packs down small and could easily be compressed further. 

The pockets are padded with primaloft too which increases the protection from radiative and convective heat loss at the hands. There has been criticism of the wire brim to the hood - I think this is unjustified. It's malleable and useful. The interior zip flap is Montane's usual high-quality offering, which I like, and there is beardguard which the Nano Puff does not have. Both those mean it surpasses the Nano Puff. It feels more robust too - I could have a UL rucksack on the Prism without fear of degradation of the Pertex outer. I first put the Prism on when we stopped for lunch at the top of Pen yr Ole Wen and the wind was causing us real problems. It had a fairly instantaneous effect.

 For those who do not know, Pertex MicroLight is a 30 denier microfibre nylon which, as a consequence of extremely tightly woven microfilament yarns, is highly windproof and manufactured to provide an effective barrier against down leakage. The fabric's tight weave enhances insulation by trapping more air so the loft of the insulating material is maximised (although a recent article on BPL would suggest loft does not necessary equal warmth). It is also constructed using DWR+ (a durable water-repellent treatment) which envelops each micro filament of the fabric with a hydrophobic polymer. This method of treatment gives remarkable water resistance which remains effective after washing but which does not impair breathability as is not a continuous coating. Where most nylon fabrics wick moisture directly through the weave, Pertex instead spreads it over a broad area by capillary action. Thus, moisture evaporates more readily. In the Carneddau, when surrounded by the damp mist within the clouds, and the wind battered us like a siege engine, I felt snug and protected. The Prism kept me warm when needed but breathed superbly as we moved fast to get below the cloud line for our camp. It is a great piece of kit.

In the warmer months, when wind chill will be more of a concern whilst moving than air temperature, I think the Lite Speed/Nano Puff combination might be preferable simply because the Lite Speed could be used alone, but as the weather gets cooler, the Prism surpasses that combination. It is very much a piece of kit I will look forward to testing in the winter months. It kept me safe in the Carneddau when the weather was anything but.


  1. I used a 1.0 on the 2007 TGO Challenge. Top kit and kept me warm most nights. Light and the hood was a good feature. That looks a good update. Still I prefer a down jacket for camp and a light fleece top like my Treble vest for the trail.

  2. With this type of jacket in fairly chilly weather, is the idea that you wear a waterproof jacket over the top of it when it rains (a lot)?.
    I'm still using the old combination of base layer / fleece / good solid waterproof, with a pertex windshell over the fleece for protection from chilling breezes when it's dry.
    I'm considering a Primaloft job for this coming winter though, the old bones feeling the cold more these days.

  3. I like the Prism, and Primaloft, because I feel more secure if it gets wet because it will still perform reasonably well - haven't tested it, but given the weather over the last 3 months in the Alps, guess I'll have the chance to test that. Geoff - I did wear a waterproof over it as the mist was extremely wet - it still breathed so well, I found it remarkable. I think the Prism is a great option for you this winter, given what you're saying. Through a lot of the early ascent, I was only wearing a base layer (Montane Bionic) before putting on the Prism around 980m up when we stopped for lunch. I did not take it off...

  4. I like the look of the Prism myself, I have a well used Flux which also uses Primaloft but it's a bit heavy to carry as an extra layer but too warm to wear on the move. That said as an everyday jacket I love it as it doesn't matter if it gets wet. The Prism looks like a good bet, not as warm or as heavy as the Flux but a better bet on the move or under a waterproof.

  5. I used it whilst we stopped for food, then underneath the LIM Ozone which is Gore-Tex Pro Shell, for several very tough (and fast) hours, and then on its own. It breathed excellently. I cannot speak as to water resistance just yet, but it felt so durable and well manufactured. The hood, also, something I thought I'd never really use, was so welcome in that 45mph wind. When we camped, my pal in the Nano Puff was losing heat a bit more than me, I think, as we were low on calories and the wind was taking its toll. Hard to say for sure as we all get colder and warmer at different rates, but the Prism was a great jacket and I'll be glad to take it on the TMB.

  6. i bought one 2 weeks ago and stiching has come undone in 4 places. i only wore it around the town a few days. i would question the longetivity of this jacket

  7. Although I found the stitching a problem on one part of the jacket, everything else has been superb. I am not sure one customer experience makes the jacket questionable but thanks for your comment.

  8. The new Prism 2 jacket is excellent though a lot shorter, heavier and warmer than the original Prism 1! Probably use the jacket for a different purpose rather than a ubber conpact light warm and waterproof layer. Fi could use her Prism 1 in Spain when it got chilly on the mountain belays but 'your' Prism 2 felt like overkill and more suited to Scotland!!!!  I'll be trying it out on our climbing and mountaineering courses over this coming winter...