Wool in summer sounds like a mistake. It is the objection every merino brand hears, and it is the one that disappears after a week of wearing the shirt. Here is what is actually happening in the fabric.
Why a merino wool t shirt runs cooler than cotton
Cotton absorbs sweat and holds it against the skin. The shirt goes heavy, clings, and stops breathing — which is why a cotton tee feels worse as the day gets hotter.
Merino moves moisture as vapour before it turns into liquid. The fabric stays light, air keeps moving through it, and evaporation continues to cool you. The fibre also has a natural crimp that holds the fabric slightly off the skin instead of plastering to it.
Add UV protection — lightweight merino carries a UPF rating of 25 — and the shirt does a job cotton cannot.
165 or 180 GSM
GSM means grams per square metre, the weight of the fabric. It is the whole system for choosing warmth.
- 165 GSM — the lightest. Running, hot days, layering under a shirt. The closest merino gets to feeling like nothing.
- 180 GSM — slightly more substance, better shape retention, the everyday choice for most people.
For reference, 250 GSM is the winter base layer weight and 320 GSM is heavyweight thermal. A t-shirt lives at the light end on purpose.
Does merino itch?
Not at this fineness. Prickle is caused by fibre diameter: anything above roughly 22 microns is stiff enough to press into the skin. Our merino measures 17.5 microns, so the fibre bends instead. If wool has itched you before, it was coarser wool — the comparison is closer to comparing sandpaper grades than to comparing materials.
Why one merino tee replaces three cotton ones
Merino traps odour-causing bacteria inside the fibre rather than releasing them. Three or more wears between washes is normal, and travellers routinely get a week out of two shirts. That is the real reason merino ends up in carry-on luggage: it is not about comfort, it is about volume and laundry.
Crew or V-neck
Crewneck is the classic shape and the easier one to layer under a half zip or jacket. V-neck sits more open at the collar and works better on its own or under an unbuttoned shirt. The fabric is identical.
How to wash a merino t-shirt
- Inside out, machine wash cold on a gentle cycle with like colours.
- Mild or wool-specific detergent.
- Lay flat to dry — heat is the only thing that shrinks merino.
- No fabric softener, no bleach.
Wash less than you think. Airing a shirt overnight restores it for another day in most cases.
Common questions
Is a merino wool t shirt good for the gym?
Yes, and it is the clearest demonstration of the odour resistance — a merino tee after a workout does not smell the way a synthetic one does.
Will it stretch out of shape?
Merino has natural elasticity and recovers its shape. 180 GSM holds shape better than 165 if that matters to you.
Is it warm enough for winter?
As a base layer under something else, yes. On its own in cold, choose a 250 GSM long sleeve instead.
Where to start
See the full range of men's merino wool t-shirts and women's merino wool t-shirts in 165 and 180 GSM.