An Introduction To The Layering Clothing System
You remember when your Mum told you to “wear your vest” in cold weather? She was absolutely right. In recent years, the establishment of new fabric technologies has created a wide range of “Technical Apparel” to suit all conditions and lifestyles and it is this area of Technical Apparel that Baselayer™ excels.
So let's explain the logic behind the “Layering System".
This is the Base Layer or Foundation Layer that's worn next to the skin. It's important to realise also that a Base Layer is NOT just for winter, they are equally effective in warmer conditions as well.
Moisture Management or Wicking, is a key element for this primary layer to eliminate moisture from the skin which natural fibres such as cotton, cannot achieve due to high absorbency. One key rule here for a Layer 1 garment is "Avoid Cotton".
The Base Layer should be reasonably close fitting or even Compression Fitting and fit reasonably close to all the contours of the body to work most efficiently but can be looser if preferred. This layer should provide the key element of “Wicking” to remove moisture away from the skin surface caused by perspiration and, where cold conditions exist, also have good Thermal properties to help maintain the body’s Core Body Temperature. In warm conditions, the Base Layer should wick moisture away from the skin to the outside of the garment where it evaporates quickly to give a cooling effect on the body. Hot Weather Base Layers have no Thermal properties and are lighter and finer in construction.
Compression Base Layers are widely used in the sports sector to improve performance and recovery after extreme excursion in both Hot and Cold conditions. Witness Olympic athletes in tight fitting running gear in warm conditions or Skiers on frozen mountain slopes.
Their compression fit garments are assisting them in muscle efficiency and the protection & recovery of core muscle groups as well as providing body temperature regulation. Base Layer garments should be very comfortable with well constructed soft seams to minimise abrasion and are mainly constructed of a man made materials or Merino Wool. Merino however, does not provide Compressive fit, just a regular fit.
Mid-Layer garments should provide a considerable amount of additional Thermal Insulation or act as a Transport Layer in warmer conditions. Cold weather Mid Layers are generally constructed in a loose weave fabric allowing for pockets of warm air to be created by the body’s own temperature. For Warm Conditions, the fabric is generally very fine and lightweight and continues to carry moisture away from the body for fast and effective evaporation. Hot Weather mid layers can also be worn next to the skin as these will also wick moisture away from the skin
The Mid Layer will, however, be far less effective if the Base Layer is not efficient to start with. Mid Layer’s should also be Moisture Wicking so that any moisture is transported to the outside of the layer for easy evaporation. Mid Layer garments are generally light in weight due to the fabrication and are ideal for mid climate conditions or as a lightweight protective layer used following exercise.
The Mid Layer will be susceptible to external weather conditions though, as wind can easily penetrate the fabric to replace the warm pockets of air created by the body’s core temperature. A light cool breeze can reduce temperatures by up to 10° and on a 0° day this creates an effect of -10° temperatures on the body. This is often referred to as the Wind Chill Factor. To avoid this, a quality and efficient Top Layer should be used as well.
The Top Layer is usually the weather protective layer. These fall into two categories, the Shell Layer for changeable conditions but not excessively wet or cold and the Outer Layer which are designed for more severe conditions.
It is essential that the Top Layer is adequate for the conditions you face but should also be of a breathable Moisture Wicking construction and well ventilated to allow the whole layering system to work efficiently.
Most quality Top Layer garments will be constructed to allow for good ventilation and often with extra Vented Zones at key hot spots on the body such as under the arms, thereby increasing the rate of moisture evaporation into the air.