Most men either ignore base layers entirely or treat them as purely functional kit with no thought given to how they sit under everything else. Both approaches cause problems. Too thick and your shirt collar bunches. Too rough and it itches through a long day. Too visible at the neck and the whole outfit reads wrong. What actually works is a base layer light enough to disappear under a shirt but considered enough in its construction that it earns its place against your skin from early morning to late evening.

We have been looking specifically at options that work year round rather than just in deep winter. Merino is the obvious answer for most of these because the fibre breathes, resists odour, and holds its shape in a way that cheaper synthetics simply do not. Fit matters too. A base layer that bunches at the waist or pulls across the shoulders will ruin whatever goes on top of it. These are the ones that do their job without drawing attention to themselves.