The design objective of an exceptional base layer is to provide warmth without trapping moisture against the skin. Traditional solid knit garments made of Merino wool or synthetic yarns do a fair job of this. They provide some trapped air insulation within the fabric and allow some “wicking” of moisture away from the skin. Mesh, however, affords up to six times the insulation value per gram of weight and, due to its porous design, allows body moisture to immediately “transport” to the outer layers. This means perspiration does not need to become a liquid to be wicked away but instead moves directly as vapor to the next clothing layer. In addition, the mesh design is much more stretchy, thus improving freedom of movement for intense activity. By varying the size of the mesh, the garments can produce different degrees of warmth and vapor transport without increasing garment weight. No solid knit garment is capable of this.

Here is a link to a Swiss study describing the benefits of Brynje mesh:


A trio of sheep standing in a field.


Wool fiber can take up to a third of its own weight with moisture without feeling wet to the body. Wool also has natural odor mitigation properties, reducing smell after several days of use. Wool blended with polyester fiber dramatically increases the function of the wool; the moisture transfer, durability and longevity is improved. Brynje uses an 80/20% blend of Merino wool and polyester, weaving the polyester into the wool. Aside from the economic benefit of a more durable garment, it is also best for the environment. Our wool is produced without chlorine, which makes it more sustainable and environmentally friendly.

EXP 4.0EXP is the first wool finishing process in the world to meet the strict criteria of “bluesign® ” and “Global Organic Textile (GOTS)” standards, and it also conforms with the “Öko-Tex standard.”

Illustration of how to wash Brynje undergarments.

Laundry Instructions

Wool is a natural fiber which does not to be laundered regularly. A global wardrobe survey in 2015 by AC Nielsen confirmed that wool garments have a longer life than cotton – as much as 50% longer. Merino wool can be worn multiple time between washings which will prolong the garment life and protect the environment.

• Hand wash or machine wash on gentle cycle with cool water (not to exceed 85°F).
• Line dry. Do not tumble dry.
• Do not use bleach.
• Do not use fabric softener.
• Do not dry clean.

Man wearing a Brynje undergarment shirt in the rain.


Polypropylene fiber has unique properties that make it very suitable as a base layer for extreme activities. Polypropylene fiber has the highest insulation performance-to-weight ratio and excellent moisture transport. The fiber does not retain moisture so there is little wetness against the skin and it dries extremely quickly. We use polypropylene mesh in our SUPERthermo® products, Arctic products, Antarctic products and Polar Fleece products. While it does not have the odor mitigation properties of wool it is an excellent choice for fishing, sailing, paddle sports and expeditions where moisture is of primary concern.

About Brynje

Brynje of Norway is a small family business with a big goal – to deliver the best performing cold weather/active base layer possible. Since 1887, they have been world renowned for quality, functionality and durability. When Tenzing Norgay and Sir Edmund Hillary were the first to summit Mount Everest in 1953, it was with Brynje mesh next to the skin. In 1994, Brynje reached the South Pole with the Unarmed Expedition. This was the first time that synthetic mesh clothing reached a pole. Now Brynje offers collections that work equally well in the beautiful Norwegian countryside as in the planet’s most inhospitable places. Follow BrynjeUSA on Facebook for news, products and expeditions.

Brynje USA