The so-called “onion principle” is often used in outdoor sports, as it allows for more precise adaptation to the given temperature conditions.
We will show you that a breathable layer structure is also possible with wool and what advantages this brings.

1st layer - Merino base layer

The most important layer for well-being during sports is of course functional underwear, as it is in direct contact with your skin.
Merino wool is not only particularly soft and comfortable on the skin, but also acts as an air conditioner. No other material manages the balancing act between cold and warm weather as well as wool fiber. It cools in the heat and warms in the cold. Sounds unbelievable? You can find out exactly what it is all about in our lexicon article "Why Merino Underwear"

But there is also a wide range of variation in this first layer thanks to the different material thicknesses that cover all four seasons. We have divided these into 3 areas:

a) Merino underwear thin = 120-170 g/m² fabric thickness
b) Merino underwear medium = 180-240 g/m² fabric thickness
c) Merino underwear thick = 250-400 g/m² fabric thickness

Category a) is suitable from midsummer to the transition period, but can also be used at very high activity levels in winter
Category b) is the all-rounder and covers the transition period and normal winter temperatures for most sports activities
Category c) is ideal for winter sports in sub-zero temperatures and for staying outdoors without sporting activity

2nd layer – Merino fleece

Why stop at underwear? You can also use Merino fleece in the second layer for extra warmth and environmental friendliness.

Fleece jackets made of synthetic fibers in particular are among the biggest sources of microplastics in textiles.

Merino wool is not only the greener choice here, but also functionally superior. Merino fleece is also available with a structured inside, which makes the advantage in terms of the warmth-to-weight-to-volume ratio even greater and also scores points for quick sweat wicking. The odor inhibition already known from underwear is also an important aspect for the second layer, especially on multi-day hiking tours.

3rd layer – wool insulation

Jackets insulated with wool can be used as a second layer or as a third layer. They are the perfect compromise between down and synthetic fiber fillings because they are more moisture-resistant than down, as well as warmer and more environmentally friendly than synthetic fiber padding.

Normal virgin wool is used for wool insulation, as the added value of merino wool in terms of softness plays no role in padding and would only make the product unnecessarily expensive.

The best-known example of wool insulation jackets is the Swisswool series from Munich-based manufacturer Ortovox. These impress with outstanding comfort and uncompromising functionality. They are windproof, robust and very light.

The natural climate of the wool and excellent heat retention when wet leave nothing to be desired.

4. Wool in harmony with hardshell jackets?

Wool not only works in combination with hardshell, no, more than that: it creates the perfect harmony because it solves a well-known problem.

Regardless of whether it is a microporous membrane, a hydrophilic membrane or a coating - if too much sweat is produced in too short a time, real-time transport becomes difficult. The same applies if the temperature gradient from underneath the jacket to the outside is too small.

The breathability of the most modern hardshell jackets has its limits and this is where wool comes into play with a trump card up its sleeve.

The wool fiber can buffer more than 30% of its own weight in moisture and release it slowly and evenly to the outside.

This means that short-term changes in the intensity of movement (e.g. on steep climbs) can be compensated for over a longer period of time and sweat build-up under the jacket is less likely to occur.