Extensively tested and reviewed by Cairngorm Treks throughout late summer through to winter 2018/19 in the Cairngorms and surrounding mountainous areas.

When the guys at UOG told us that they were sending up the newly updated Montane Prism jacket we were very excited. The Prism is a classic cold weather jacket built for life amongst mostly all outdoor activities, well known for being dependable and hard wearing. Over the years the Montane Prism has undergone a few changes and it appears the updated 2019 version is of no exception.

The most noticeable difference is within the appearance and shape of the Prism. Montane have removed the large vertical panelling around the mid body, and instead replaced it with smaller diagonal panelling around the chest area. This is an approach we have seen Montane commonly adopt amongst their more technical jackets. Thinner baffles make for a more compressible jacket but with the extra seams required there is an increased loss of heat. The Prism has always been regarded as an insulated jacket that works best whilst on the move, and this change in design should amount to better regulation of warmth and breathability. Internally, large horizontal panels run all the way down the jacket with the stitching only holding the insulation in place from the inside and not continuing to the outer fabric. Montane have spent time to areas which need to retain warmth compared to those in which breathability is key.

The newly updated lining uses a Nylon 20D Featherlite Mini Rip-Stop fabric. On appearance it’s quite shiny and feels great against the skin. The outer fabric is a 30D Pertex Quantum with DWR. This choice of material is becoming very popular especially with lighter synthetic fill jackets like the Prism. This combination provides excellent breathability, whilst also giving great protection against wind and lighter showers.

Montane have again chosen to use 40g/m2 PrimaLoft Silver ECO insulation throughout, and why not? This is a tried and tested combination and provides enough warmth for on the move activities in the winter whilst also being a light and packable option for spring and autumn activities. Montane have chosen PrimaLoft's updated version of the Silver, with the ECO element standing firmer than ever. A full 100% of the fill now coming from recycled products. This combination of updated materials and build means that the Prism also improves on weight and packability. Compared to the previous model it’s down from 440grams to 390grams based on a medium size.

The choice of insulation isn't going to give you the comfort, super low weight, or packability of a down alternative, but where it does stand out is with its ability against moisture. Too many times we have been out with clients and they have issues with their very expensive down jackets not performing as they had hoped. It almost always comes down to the same problem, Scottish weather! Damp cold conditions mean a lot more care has to be taken with a down jacket. This is of no issue for the Prism with its ability to combat moisture being very impressive and even when wet still holds its insulating properties. It can also be washed at home so no need to worry about getting it dirty with an expensive trip to the dry-cleaners.

We gave the Prism a hammering in heavy rain and sleet on a trek to Stob Ban (Mamores). The 30D Pertex Quantum outer fabric performed better than expected and on further inspection feels to have a thicker coating applied than previous jackets we have used. We wanted to test the limits of the Prism and after just over an hour of persistent rainfall it finally gave up and started to soak through. Although we would never let a jacket get as soaked as we had let the Prism, we were impressed it stood up to such bad weather for as long as this. It also gave us a good chance to see how it would dry out once wet. Unfortunately, with the high amount of moisture retained, the PrimaLoft Silver insulation didn't dry out as impressively, with damp patches still present when we got back to the car. Although we believe on a warmer, brighter day the prism would have dried out more efficiently and didn't dampen our faith in the Prism's abilities. During the heart of winter, ice and snow simply brushed off, and if heavier precipitation persisted then putting on a waterproof shell kept us completely free from the elements without restricting breathability and overheating.

The overall fit of the Prism still adopts a loose-fitting style, although has been slightly shaped more in keeping with the contours of the body. Instead of using a stretchy material to work in tune with the body and prevent the jacket riding up and exposing skin, the overall shape is slightly increased in size to do a similar job. Full movement is undeterred whilst at full stretch or bending over working around camp. You also don't have to be an athlete to enjoy this style of jacket and it feels comfortable whilst climbing hard or alternatively sitting around camp.

We believe Montane to be one of the best companies for attention to detail when it comes to the hood. The Prism's hood is fully adjustable, large enough to accommodate a helmet, and also has a wired peak. Primaloft Silver Eco continues from the jacket through to the hood so there are no colds spots.

Pockets are very generous in size, easily accompanying items needed at hand for winter activities. A full-size map and compass along with a large pair of gloves will stuff into the hand pockets, with a smaller chest pocket fitting a mobile phone or GPS. On previous models, Montane added an extra layer of insulation on the hand pockets to double the amount in total to this area. Within the updated version is appears Montane have kept the insulation consistent throughout the entire jacket, although with this being a sample piece this may change. Zippers throughout are easy to handle, even whilst wearing gloves, with the front zipper also being updated to the lighter YKK Vislon.

We received the Prism in Black/ Alpine Red. The two colours working well together, and we liked the simplistic approach. There are a few more colour choices available with a brighter choice of Arbor and Citrus Green, Narwhal and Electric Blue, and a more subtle Shadow / Alpine Red.

Our Verdict

Montane have been wise not to too drastically alter the Prism. Changes that have been made only enhance what was already a very good jacket. The updated baffles and lining work well to better regulate body warmth and breathability. Whilst the change to a fully 100% recycled Primaloft Silver Eco shows Montane's commitment to a more sustainable product. This style of jacket may not be technical enough in one area to suit all but as a base to most outdoor activities if we were to pick just one insulating jacket for use in the Scottish hills the Prism would be a great choice. The sign of a good jacket is one that you see people wear years later after purchase. The Prism has always fitted into this bracket and we can see the updated Prism once again becoming a popular, hard wearing and dependable jacket.

Cairngorm Treks is a small family business based in the picturesque village of Tomintoul in the North East region of the Cairngorms National Park. They provide bespoke Mountain Guiding for Single Day Walks and Lightweight Multiday Trekking experiences, including wild camping, in the stunning Cairngorms wilderness and surrounding areas. Whether in the high mountains or lower valleys, their Multiday Treks are equipped with high quality, lightweight camping and trekking gear. They only work with small groups and, whatever your ability, pride themselves on designing your outdoor experience completely to your needs and with professional guidance and expertise. Adventure is waiting...