The Layering System
This is the term for a system of clothing that can be tailored to the individual and their needs. In its most basic form it takes the form of three layers, however there are variations and exceptions.
Worn next to the skin it has two primary functions. First it draws sweat and vapour away from the skin, leaving you feeling dry and comfortable. If your skin is damp the body can cool down rapidly. Secondly it can trap a thin layer of air next to the skin to provide a small amount of insulation.
This is worn over the base layer and is to provide insulation and help to prevent heat loss. It also allows vapour that has passed through the base layer on its journey away from the skin. There are numerous options of mid layer and it is here that much customising of the system can be done.
This is the outer layer. It must keep wind and precipitation from penetrating, whilst allowing perspiration out
It is possible to wear any combination of the three layers above to suit the ambient conditions. We can now take a detailed look at the various options available in each of these layers. It will then become apparent how versatile this method of clothing is:
In our opinion this is the most important layer because if it is selected incorrectly it will have a dramatic impact on your comfort. It is also the layer you are likely to wear most of the time. There are many misconceptions about base layers and they get referred to frequently as thermals. The options for fabric are:
Warm when wet
From a renewable resource
The choice here is vast but can be polarised into fleece of various thickness or natural products like merino wool:
Usually 200gm weight, it is the most popular for general use
There are two main ways in which a shell garment works:
There are other garments to consider when choosing your layering system. They can be used to good effect either as a replacement or as an addition to any of the above:
In deep cold conditions or periods of cold inactivity, so many layers may be required to insulate that movement is restricted. In these conditions a duvet jacket is useful. They can be made from either natural down or a high loft synthetic insulation. They are not normally waterproof so care needs to be exercised when they are used. They do however provide a much greater degree of warmth than the equivalent weight of fleece.
This is a growing breed of garment and becoming popular with those that understand the limitations of fleece whilst not wanting the restriction of a traditional hard shell. These garments are not usually totally waterproof but do have a very high degree of breathability. They are ideal for highly active sports in non-extreme climates.