A layering system is a complex thing. What works for one person may not work for another. Layering is the best way to keep warm on the mountain, it is more versatile and offers far greater warmth effectiveness than a single thick layer. The base layer is the base of the layering system; it is vital to get the correct base layer. To help you choose the right base layer we have put together a list of key areas that you need to think about when looking for your next base layer.
The weight of a base layer has a massive effect on the warmth it produces. The heavier the base layer, the warmer it will be. Generally, there are three different base layer weights.
A lightweight base layer is a thin layer that goes next to your skin. It is critical that this layer is comfortable and is fitted closely for the best moisture management. When worn on its own, it is ideal for mild to cool conditions with a high level of activity involved.
A midweight layer can be worn as a warmer first layer or as a second layer, over a next to skin layer to provide a combination of insulation and moisture wicking. On its own, it is ideal for moderately cold to cold conditions with a medium level of activity. Combined with a lightweight layer underneath or a heavyweight layer over it, to maximise its warmth capabilities.
Almost always worn over a lighter weight layer, a heavyweight layer is designed to add extra insulation. These base layers are generally worn looser that lightweight layers, and are often mistaken for mid layers due to their thickness and insulation capabilities. Heavyweight layers are ideal for cold conditions with any level of activity involved.
Different materials work in different ways to optimise the bodies temperature when out in the cold. The majority of baselayers today are comprised of either synthetic fibres or merino wool. Both of these fabrics have wicking properties that remove perspiration away from the skin and disperse it on the outer surface. Both materials have their benefits and drawbacks in different situations.
Synthetic base layers are largely made from polyester and polyester blends. These base layers are quick drying, lightweight and have superior wicking abilities. As they use man-made fibres they generally cost less than merino wool base layers, but they are not as warm.
These base layers use the wool from merino sheep, a resilient breed of sheep found in the New Zealand Southern Alps. The benefits of a merino baselayer outweigh the slightly higher price tag that it carries with it. Merino wool garments are very soft and have very fine fibres, which means they bend easier than synthetic or traditional coarse wool fabrics, making merino an ideal non-itch fabric to sit next to your skin.
It is also very pliable so will allow freedom of movement, and reshape easily after washing.
Merino wool baselayers offer a higher standard of warmth compared to its synthetic counterparts. The natural fibres have developed great thermal retention properties as it protects the merino sheep during the coldest of winters, even when wet.
Unlike synthetic baselayers, merino wool has antibacterial properties due to the lanolin and keratin wax produced by sheep. These two substances have powerful antibacterial and antimicrobial properties that help to protect from water and bad odours forming. If needed a merino wool baselayer can be worn for days, even weeks at a time without needing to be washed.
The fit of a base layer is extremely important, a poorly fitted base layer will be uncomfortable and ineffective. As it is the first layer, the nearest layer to your skin, you will want a fairly close fit. The base layer helps to conserve your body heat, whilst wicking away any moisture and perspiration.
A looser fitting garment will allow air to flow between the base layer and your skin, removing any heat. Heavyweight base layers can be worn looser, over a close fitting first layer. Whilst it may be a looser fit heavyweight base layers will still have a close fit.
A base layer top should have a tighter fit, cover all exposed areas, and give you the ability to tuck it into your outer layers. When sizing, use your standard t-shirt size as the fit will be snug by design, there is no need to size down to get a tight fit.
Bottom base layers will also fit closely. As with top base layers, a snugger fit will offer more warmth. They should reach the bottom of your lower leg and rest around the ankle area, unless it is a three-quarter length. Going with the same size as your standard size will be adequate when sizing baselayer bottoms.
Modern compression gear uses 'graduated technology' constructed from specially designed seams and panels. This means that it puts the most pressure on your extremities such as your wrists and ankles, and gradually reduces this pressure towards your heart.
This technology delivers a controlled amount of pressure, in all the key places, to improve your venous return - the rate of fresh, oxygenated blood to your muscles and deoxygenated blood back to the heart - and reduce lactic acid.
Studies have shown that consistent pressure applied by compression wear improves the flow of oxygenated blood by up to 40%. This increase in oxygen has significant benefits that include; increased recovery speed reduced muscle fatigue, increased circulation and heat, less cramp and reduced risk of injury.
When buying compression clothing you’ll notice that your recommended size is not determined by your regular measurements but by BMI sizing using your height and weight to ensure it fits your body properly. This means compression clothing will be much tighter than standard baselayers, but not to be painful or restrictive to your movement.
Don’t be fooled into thinking the tighter it is the better it will perform. It must fit your body properly; too tight compression can prevent circulation. Most importantly, it should be comfortable, a brand that works for one person may not work for another.
The Layering System
Layering is the best way to keep warm. Layering works by trapping air which is heated by your body temperature, the more layers, the more air is trapped. This means that multiple layers are far more effective than one single thick layer. A layering system for skiing should consist of a base layer, mid-layer and outerwear.
The amount of layers you wear is a personal preference depending on the weather conditions and how much you feel the cold. Finding a base layer that best suits your needs is just the first step in finding your perfect layering system. The mid-layer is the next, and possibly the most confusing step. See our Art of Layering: Mid-Layer to help you choose the best mid-layer for your needs.