Lightweight summer base layer

Smartwool’s latest tee-shirt, new for this summer, comes with the option of different graphics printed on the front as well as different colours. The one I’ve been testing has the same graphic as in the picture above but is black in colour with white writing. There’s a version with just a small Smartwool logo too.

The tee-shirt is made from a thin 56% merino/44% polyester material and designed to be cool in hot weather.  Each thread of merino is wrapped around a polyester core  so there’s always soft wool next to the skin for comfort. The purpose of the polyester is to speed drying time and increase durability. Smartwool says the Sport 150 still has the moisture management, temperature regulation and odour resistance of merino.

The Sport 150 has a reinforced neck to stop it sagging, flatlock seams to minimise rubbing, and offset shoulder and side seams to prevent chafing from a pack. The Large size weighs 165 grams and is quite loose on me, which I prefer in hot weather.

I took the Sport 150 on the TGO Challenge in May. The first week I mostly slept in it on chilly nights, preferring a synthetic shirt for walking in the heat (mainly due to the pockets). The second week was wet and cool. I wore the tee-shirt under the shirt during the day as well as sleeping in it. As a base layer it worked fine, never getting more than slightly damp and drying fast. At the end of the Challenge when it had been slept in for eleven nights and walked in for six days it didn’t smell, the merino having worked its usual magic.

Since the Challenge I’ve won the Sport 150 on hot days and it’s been comfortable and cool. I think it’s a great base layer for year-round use, with or without graphics.