Nikwax® Basewash® image 0
Brynje USA

Nikwax® Basewash®

Sale price$9.50 USD

Built to keep you dry, warm, and moving through cold, high-output conditions.

Size: 10 oz

Built to keep you dry, warm, and moving through cold, high-output conditions.

The Super Thermo Long Sleeve with Inlay is made for cold-weather movement where sweat, wind, and shifting effort levels can leave you chilled. Worn directly against skin, Brynje’s open mesh construction helps move moisture away from the body while creating a warm insulating air layer under your next layer.

Best For
Hiking
Backpacking
Skiing
Fishing
Mountaineering
Winter Work
Gender Unisex or gender-specific depending on style
Weight Varies by product and size
Fit Notes Fit varies by product and style. Refer to the product size chart and individual product details for guidance.
Specific Measurements Measurements vary by product and size. See the product size chart or product details for additional information.
Made In Varies by product
Material Material composition varies by product
Construction Technical construction varies by product and is designed around the intended use of each style.
Product Features Features vary by product and may include product-specific technical, comfort, fit, or performance details.
Fit Fit varies by product and style. Refer to the product size chart and individual product details for guidance.
Measurements Measurements vary by product and size. See the product size chart or product details for additional information.
Origin Varies by product
Optimal Temperature Range for Highest Performance

20°F to 45°F

(-7°C to 7°C)

Recommended for sustained cold-weather movement when integrated into a technical Brynje mesh layering system.

Extreme Cold Mild / Moderate
-20°F -29°C
20°F -7°C
45°F 7°C
60°F 15°C

Temperature windows are approximate and vary based on personal metabolic rate, sustained activity levels, wind chill, and current atmospheric conditions.

Find Your Perfect Fit

1. Select Garment Category
2. Select Fit Preference
3. Dial In Your Measurements
Your Recommended Size
MD Optimal Match

Why Mesh Works

Mesh doesn’t trap sweat against your skin like a traditional flat-knit base layer. Instead, the open structure creates small pockets of air that help insulate while allowing moisture vapor to move away from your body.

Brynje open-mesh performance breakdown diagram
That means:
Less clammy fabric against skin
Better comfort during stop-and-go activity
More warmth when layered correctly
Faster drying performance in cold, wet conditions

Performance Layering Mechanics

Toggle between the modes below to see how the mesh manages moisture and warmth.

SYSTEM KEY
Water Vapor / Sweat
Body Heat
SKIN
OUTER LAYER
Next-To-Skin Only: Open mesh cells dump excess heat while channeling moisture vapor away from your skin.

Customers are saying

4.80 ★ (994)
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+ CHAPTER 05 / COMMITMENT We don't do seasons. We don't do trends.

We make garments that last.

Repairable

Designed with construction methods that allow for easy repairs, extending the life of your gear for decades.

Timeless

Our aesthetic hasn't changed much since 1953. We focus on function over fashion cycles.

Tested

Every stitch is proven in the world's harshest environments before it ever reaches your back.