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Base Layer

Importance of Base Layers

There is a phrase that has long been said amongst mountain climbers, “if you wear cotton on a mountain, you won’t survive”  It is true that cotton has a pleasant feel and retains heat well, qualities which make cotton great for casual wear. But when climbing a mountain, cotton’s highly absorbent properties can be harmful and when large amounts of perspiration accumulate in your clothing, being unable to dry out becomes a problem. Normally, perspiration is one defense mechanism to the body which is to cool the body through evaporation. But if your clothing cannot dry out and remains wet for an extended period, the body begins to lose unnecessary amounts of heat by conduction through the damp clothing and evaporation. Gradually the body can lapse into hypothermia and if no action is taken, eventually death.

Hiking, trekking and climbing are all activities which involve swings in body temperature. When active, the body produces heat and perspires, and when finally emerging onto a ridge blasted by cold winds, the body temperature can drop to the point of shivering. Sudden rises or falls in body temperature can result in life-threatening issues such as hypothermia. It is therefore extremely important to consider the base layer. A base layer, which also known as underwear, is the layer closest to your skin and should act as a constant 'second skin' throughout your activities. Base layers provide a layer of warmth while absorbing and evaporating your sweat to keep you feeling warm and comfortable. Each material of base layer has its own unique characteristics; quick-drying properties, moisture absorbency, elasticity and heat retention. Choosing the material is essentially choosing how you plan on maintaining your body temperature. Let Montbell introduce you the materials of Montbell base layer, Super Merino Wool and Zeo-Line.

Super Merino Wool

A natural moisture absorbing heat generating material that keeps you warm from the moment you wear it. Used for long-term activities at low temperatures. Variation of Super Merino Wool base layer:

  1. Thin (Lightweight)


  • This model is thin but it has high heat retention. It is ideal for layering and will be widely used throughout the year.
  • Materials: 92% wool + 8% nylon
  1. Medium weight (Middleweight)


  • With moderate warmth and excellent stretchability, it is useful for everyday activities and winter sports.
  • Material: 100% wool
  1. Thick (Expedition)


  • Hybrid underwear made with Montbell's original technology that combines the best heat retention and quick drying in extreme cold areas.
  • Materials: 79% wool + 18% polyester + 2% nylon + 1% polyurethane


Unique high-performance synthetic fiber with excellent quick-drying and heat retention. Used for activities that repeat stop and go. Variation of Zeo-Line base layer:

  1. Thin (Lightweight)


  • Excellent quick-drying, lightweight, suitable for extreme exercise during cold season or water sports in summer. It is a versatile model that worked all season.
  • Material: 100% polyester
  1. Medium weight (Middleweight)


  • It has an appropriate amount of heat retention and quickly absorbs and diffuses sweat to keep the bare skin dry. Ideal for activities that repeat stop and go such as mountain climbing and tour skiing.
  • Material: 100% polyester
  1. Thick (Expedition)


  • This model is ideal for the winter when warmth is important, assuming it will be worn in extremely cold regions. The three-layered fluffy air layer keeps you warm.
  • Material: 100% polyester


Why Choose Montbell Underwear?

  1. Warmth Lasts

In the outdoor field, underwear that responds to unpredictable weather changes and changes in outside temperature due to differences in mountain elevation is required.


  1. Prevent Cold Sweat

Even during the hot season, sweating during action may cause cold sweat. If you continue to wear underwear that retains water, your body temperature will be lost, causing you to sweat. Therefore, it is important to prevent sweat chills and protect yourself from exhaustion and discomfort when outdoors.


  1. Suppress Odor

It has an excellent deodorizing effect and keeps you comfortable. You can wear it with confidence even in situations where you sweat a lot.