Thermawool 2.0 Half-zip by Terramar Sports

Back in 2013 when I hiked the John Muir Trail I took two tops to keep me protected from the sun and comfortable in the cool mornings and both of them were by Terramar Sports. The first was the now discontinued Smartsilk BaseLayers and the other was the Terramar Sports.

With a ~15 lb baseweight and a 40 litre pack I was going for lightweight packability that would be warm enough for the cool mornings, protect me from the sun and of course keep me smelling fresh after a week on the trail. The Thermawool 2.0 Half-zip did not disappoint.

Let’s take a look at the features and then move on to my thoughts.

Features:

• 30% Merino Wool
• 180g (per square meter of fabric)
• Super Fine Merino Wool
• Flat Stiched Seams
• 1/2 zip
• Layering System 2.0 (Light/Midweight)
• MSRP: $65 (Shop Thermawool on Amazon)

Testing:

These items have not been retired in the two years I’ve had them… except for one caveat (read on and I’ll explain). I’ve worn this layers with other base layers (the Smartsilk for example) as well as alone on the John Muir Trail and countless other adventures since.

 

 

Performance:

We are huge fans of Merino wool. The characteristics of these super fine natural fibres makes it an ideal outdoors and backpacking fabric. It’s warm, breatheable, non-itchy, and odor resistant.

The flat stitched seams mean that even when warm by itself when wearing a backpack for long days of hiking we didn’t develop sore spots, rashes or itching. Even when we were caked with salt due to perspiration we didn’t feel discomfort.

 

 

The 180g fabric is typical of the lightweight merino wool offerings of most brands. It’s light enough to wear in warm days by itself and provides sufficient warmth for cool mountain mornings when layered with a lighter base layer. We did develop a small hole when we snagged it on a sharp object, but that’s expected (and it hasn’t grown). And no, that’s not the caveat.

A half-zip is the ideal choice for a layer in my opinion. The slight increase in the weight of a zipper is worth the benefits of temperature regulation that it offers.

The MSRP of $65 is right in line with similar Merino offerings and matches the details of the high performance and popular Merino Wool.

 

 

So what’s that caveat I was speaking about? Thermawool is apparently a girl magnet. No, I don’t mean it makes you irresistible… although that may be true. I mean that my wife has claimed all my Thermawool layers for herself. So if you want to pick up some Thermawool layers, you may want to pick up the ladies version as well.