Base, mid and outer layers—an introduction to how to layer your clothing properly in order to stay dry and warm outdoors
HISTORY OF THE LAYER SYSTEM
Although mountain clothing has always been designed with several layers of garments, we can trace the birth of the three-layer system, as we know it today, back to 1986, when the Norwegian brand Helly Hansen proposed this combination as the perfect solution for mountaineers and climbers.
Two key factors at the time were the development of base layers made from synthetic fiber and the creation of the first jackets with a waterproof and breathable membrane. Before then, waterproof jackets were not breathable, resulting in extremely limited use and excessive sweat for anyone who used them during highly aerobic activities, like mountain and outdoor adventures. However, these developments opened the door to the design of a truly effective moisture and temperature management system.
PROTECTION AGAINST MOISTURE AND COLD
To keep safe on the mountain in less than favorable conditions, keeping warm and dry is a must; if not, you risk hypothermia and its serious consequences. There are two major threats you have to look out for:
- The elements: make sure you keep wind, snow, and rain out; if you get wet, your body temperature lowers.
- Moisture: despite the low temperatures often found on the mountain, sweat can soak into your clothes. When you stop, your body temperature will drop, which could result in serious problems.
That is, not only do you have to protect yourself against external elements, you also need to keep dry when it comes to moisture from the inside.
The layer system is the best solution to this problem. There have been many improvements and advances in both materials and design, but three decades later it is still the most popular system in outdoor clothing.
HOW TO LAYER
The basic or standard system consists of three layers. Each layer has a different function related to the ultimate goal of protecting you from external elements and/or moisture produced by your own sweat. To that end, we look for different features and specific materials and designs for each layer.
Base Layer
This is the layer that comes into contact with your skin. Made in quick-drying materials like synthetic fibers and merino wool, the base layer serves to keep the body dry, wicking sweat away towards the second layer. It can also help retain heat in winter, but this is not its main purpose. Base layers come in different thicknesses so that you can choose one that best fits the outside temperature and the aerobic intensity of your planned activity.
How to Choose a Base Layer
Mid-Layer
The purpose of the mid-layer (or middle layer) is to retain body heat. It must also be breathable in order to collect and wick away the moisture from the base layer. There are many mid-layer options to choose from. To begin with, there are the traditional polar fleeces, which are great for trapping in heat and moving moisture away from the skin. On the other hand, they provide little protection against wind and rain. Softshell jackets can also serve as a middle layer. These can stretch for movement and are abrasion resistant (good for climbing or mountaineering), although their greatest advantage is protection against rain and wind. This protection, although more limited than a hardshell, means that a fully waterproof outer layer in light rain or wind is not always necessary. Softshell jackets do a good enough job repelling water in these cases while being more flexible, comfortable and breathable than hardshells. A third excellent option for a mid-layer is the lightweight insulated jacket. More versatile than fleeces, they are also lighter. For the same heat retaining capacity, an insulated jacket takes up minimum space when compressed, an important advantage when carrying packs with limited space or when weight is a factor. Although insulate jackets handle moisture from the base layer well, polar fleeces have a slight advantage, which is why fleeces are still highly popular and often used, particularly in warmer conditions or extremely intense activity.
How to choose a mid layer
Outer Layer
The outer layers are jackets with waterproof and breathable membranes. These membranes (such as Gore Tex) keep rain, wind and snow out while also wicking away interior moisture. Just like with the base and middle layers, there are many options to choose from when it comes to picking an outer layer, depending on the type of activity and the weather con ditions. Two-layer outer jackets are available; these are the most versatile and comfortable, and will serve in most activities in not very extreme conditions when you need protection against rain and wind. On the other hand are the three-layer hardshell jackets. So called “bombproof,” these jackets are designed for the toughest conditions, like those found in mountaineering, where protection against moisture, wind and abrasions caused by rocks is essential. The disadvantage of these garments is that they are more rigid and uncomfortable, given the added protection they provide. Finally there are technical lightweight jackets. They work well for activities in which weight is everything, but they are much less resistant to the abrasions from rocks or backpacks.
By combining these three layers you can create a system that protects you from external elements while also wicking away sweat, keeping you dry and therefore warm and safe.
The North Face Apex Flex GTX® 2.0 Jacket – a Gore-Tex three-layer shell jacket with innovative flexible materials.
ADAPTABLE SYSTEM
Another advantage of the layer system is its versatility. As each layer is an independent garment, you can take layers on and off as your activity level or the weather changes, regulating your comfort at all times. On many occasions (light rain and warmer conditions, for example), a third outer layer makes you sweat more and increases discomfort, making the enhanced protection of the outer layer unnecessary. Simply wearing a base layer and a softshell will provide more than enough protection and keep you dry and comfortable. You can also add an ultralight outer layer should the rain unexpectedly intensify. In intense cold or when the cold is more noticeable (like when you stop to rest), you can add an extra fourth layer, such as a down insulated jacket, to trap in heat. These extra layers are lightweight and you can carry them in your backpack, and you'll be prepared for any contingency without significantly increasing the weight of your pack.
Below is a summary of the most typical layer combinations to trap in heat, the conditions under which you should use each combination, and the reasons why.
Rab Women’s Microlight Alpine Jacket down-filled insulated jacket 4th layer for extreme cold.
BASE, MID, AND OUTER LAYERS AT BARRABES
Now that you understand how the layering system works, you can explore our selection for each layer in Barrabes. You can also contact our customer service department for more information.
Base Layers
Mid-Layers
Men’s synthetic insulated jackets
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Women’s synthetic insulated jackets
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Outer Layers
Men’s lightweight technical jackets
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Women’s lightweight technical jackets
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Insulated Jackets
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