Out of all the equipment we have received of late the Rab Kaon jacket has certainly been most interesting and, at the same time conflicting. First of all, let’s not mess around, this is one fine looking jacket. In Dark Sulphur, with its small panel design, it’s an eye-catching garment but that’s not to say this is a fashion piece. This is a fully technical jacket packed full of innovative design elements. Rab strive to produce equipment using the latest fabrics and insulation types, and the new range of Rab clothing have really pushed the boundaries. Out of all the recent releases the Kaon is possibly the best example of this, some areas make sense, some elements are confusing. What we can say about the Kaon is it will certainly divide opinion.

In a size medium, the Kaon weighs in at a minuscule 242 grams. Rab have certainly designed this with a weight conscious mind and have created a down layer that you do not feel bad about keeping in your pack as it takes up such little room.

The fit of the Kaon is described as slim, but we would say it’s more of a 'relaxed slim.' It hugs the body well without feeling restrictive. It's not a layer that is going to fit over much more than a thin base layer, and for good reason which we will discuss in more detail later in the review. There's plenty of movement in the arms and with the extended back we never had an issue with any fabric riding up and exposing skin. It has to be noted that for our taller guide they did find the arm length a little bit short so a size up from normal might be advised.

When fully zipped, the neck fits nicely to the chin keeping out any unwanted drafts. Unfortunately the hood doesn’t fit as snugly. This means that on blustery days the hood can easily be blown out of place, and with no adjustment points it is better suited to being placed underneath external layers for mountain walking. We believe Rab have designed the hood with alpinism in mind, as the generous sizing has a solid fit when placed over a helmet. The cuffs of the Keon are free of adjusters or Velcro strapping, which is fine as the elastic fits tightly around the wrist or over a lighter weight glove.

Atmos lightweight ripstop nylon lining is certainly very nice to wear even when placed directly against skin. It’s so soft to the touch that it became an instant hit around camp. The Kaon can comfortably be worn throughout the night to provide an extra warming layer or as a great option for first thing in the morning to take away the dawn chill.

One of the most notable aspects of the Kaon is the lack of pockets, more so that it only has a single chest pocket and even this is quite small. It's a bold move from Rab that has certainly divided opinion among our guides. The removal of pockets offers a more streamlined jacket, free from the usual issues whilst wearing a harness or waist strap of a rucksack. It also lends itself to be worn year-round as an adaptable mid-layer, making multiple layering more comfortable. But… even after a full year of use, we still find ourselves reaching for a pocket to quickly store an item, or place hands when stood still or resting at camp. This is simply out of habit and for many, including some of our guides, and is a feature that may turn people away from purchasing the Kaon.

It becomes clearer why Rab have taken this option when you consider another notable feature with the Kaon which is the use of both synthetic and down panel insulation. Rab claim this is to achieve, "the ideal balance of warmth, protection and movement." Much of the body is 800 fill power European goose down, these are seen in small panels which loft extremely well considering the compact pack size. Stratus synthetic insulation is located over shoulders, cuff area, hips, and hood, and make up areas in which down could lose its insulating qualities. These are areas in which moisture will most likely build up, or where gear will compress the insulation, such as rucksack straps/harness. It’s not instantly noticeable which area is made of which fill unless you rub it between your fingers. The insulated panels are stitched through which helps keep the fill in place but also aids breathability. An important rule with clothing of this type is staying dry. When working hard, especially in the colder months, keeping moisture from building up is a must.

To further improve breathability and save on weight, Rab again included a design element which divided opinion in the form of the non-insulated Pertex Quantum Air underarm panels. The fabric panels are very thin and our initial thought on this was that it would make the insulating properties of the Kaon greatly unbalanced. In use, we quickly realized they are a great feature making for a jacket with a nice flow of air that feels very natural to wear, especially when working hard on steeper ground. This is most apparent when combining the Kaon with a hard-shell jacket. It’s not uncommon for most waterproof shells to included pit zips which offer a decent way to dump heat or have open whilst on the move to regulate body warmth. The underarm panels of the Kaon work in perfect harmony with multiple layers an especially important feature as the Kaon does have a major weakness.

The Atmos lightweight ripstop nylon outer fabric is very soft and pliable but is also very thin. As wet weather sets in the Kaon becomes saturated easily and quickly. Although the Rab fluorocarbon free hydrophobic down does a decent job of not completely losing its insulating qualities, this is not a wet weather friendly jacket. Albeit, it does dry quickly due to its lightweight nature, if weather conditions are looking patchy for multiday activities a bit of consideration and care will be needed.

When you look again at the placement of the Stratus synthetic insulation it makes sense that it was never Rab’s intention to have this as a jacket in which you can get away with a bit of rainfall. Sleeves, hood, and upper body are all areas in which the odd bit of moisture can penetrate clothing even whilst wearing the most solid hard-shell. We spent many days with waterproof shells needed for a full days walk, the Kaon was the perfect solution to have underneath due to its high breathability and warmth directed to the core.

With no insulation under the arms it also makes for a much nicer time when a using a larger backpack with less fabric bunching under the arms.

Our Verdict

We found the Rab Kaon to be a jacket for all season use. Light and compact we very rarely ventured out without it having some role within out kit. In summer it became a layer perfect for taking away a slight chill, whilst in the colder months it became a part of our larger layering system. Rab have managed to save on weight without cutting performance with some very clever design elements. This paid off in being one of the most comfortable insulating layers we have used. Intelligent insulation, and high breathability means that when working hard we found a natural balance between warmth and breathability. In the inevitable areas where moisture could build up, or in which the fill could be compressed, the switch to Stratus synthetic insulation certainly helps to keep the Kaon in top shape. There is the obvious point of debate which is the removal of the usual front pockets. On one side you have a more streamlined jacket that combines well with additional layers, whilst also avoiding the usual issue of not being able to properly access pockets when wearing a climbing harness. On the other side not having a place to keep your hands tucked away, or quickly store items, is going to deter some people from choosing the Kaon.

Trek Scotland 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...