Also known as the Onion System. This simply means wearing different layers, where each layer has a different purpose. Mainly you can divide them into three different layers; base layer, mid layer and the shell. This doesn’t mean that you only wear three things. One layer can contain more than one piece of clothing.
The base layer
The base layer’s purpose is to transport the moisture away from the skin and provide a first layer of insulation. This is the layer you will feel on your skin, and there are two main fabrics used for this layer.
Synthetic fibres – These fibres made out of plastic (polyester, polyamide, etc.) are fast drying and are super lightweight. They’re also easy to wash, crease free and have a good stretch. But do tend to get stinky after multiple uses without washing.
Merino wool – Originates from a Spanish sheep who’s use dates back to the 18th century. When it was one of the biggest motors for the Spanish economy. Nowadays most merino wool comes from New Zealand, Australia and South America. It has a very nice feel against your skin, unlike the wool in your old knitted Christmas jumper.
This wool is itch-free and doesn’t get smelly as fast as other materials. This is because of the fibre’s texture and natural antibacterial effect. It also offers a natural climate control, that can keep you warm in cold conditions but can also cool your body when you overheat.