Layering Up - Part 1

The three-layer system is the widely recognised way of kitting yourself out for hill walking or trekking, but the basic layering system is also transferable to a wide range of outdoor pursuits: from cycling to skiing and from sailing to mountaineering.

In its simplest format, layering up looks like this:

•             Base Layer

•             Insulation Layer

•             Shell Layer

The Base Layer

As it suggests, the base layer is the first layer and is the layer that sits next to the skin. Its main function is two-fold: to trap warm air next to the body to keep you warm, and secondly, transfer moisture (sweat) away from the skin and out to the next layer to regulate body temperature to help maintain a comfortable working level. 

A base layer works best if it sits comfortably close to the skin to allow ease of moisture transfer.

Insulation or mid-layer

This is where the ubiquitous fleece comes into play. To function properly, the insulation layer is sandwiched between the base and outer shell layers. The mid layer again helps trap warm body air but also should be capable of transferring (wicking) moisture to the outer shell layer. 

Aside from the fleece, many lightweight insulated jackets, body warmers and softshell garments can also work well as mid layers.

Shell Layer

The shell, or outer layer, is the protective element of the three-layer system and fundamentally the most important item that you will purchase. Ideally the shell layer should be fully wind and waterproof, well made, will work hard at transferring moisture away from the inner layers, and be totally suitable for your intensions.

I.e. a cheap pack-away smock is far from suitable for the Cairngorm Mountains of Scotland at any time of the year.

Please note: all, with the possible exception of the mid layer, the above example can relate to the lower half of the body too, i.e. Long Johns and waterproof over-trousers.