SMARTWOOL NTS MID 250 ZIP T £90

Merino wool comes in different grades and Smartwool uses an exceptionally soft version that makes this top feel more comfortable against the skin than other base layers. The material is quite stretchy, which increases comfort, and it’s naturally antimicrobial so it doesn't get whiffy easily. You get the usual neck zip for ventilation and plain cuffs; the body is slightly short but still long enough to tuck in. There are some drawbacks: it’s less durable than bi-component materials and it can become saturated with moisture, so it may be better suited to less sweaty people. For general walking, however, it's the most comfortable choice by far.

VITAL STATS Material merino wool Weight 284g (size men’s M) Sizes S-XXL (men’s); XS-XL (women’s) www.smartwool.com