Cold at eight, warm by two, cold again by six. The jacket gets the credit for coping with it. The shirt underneath is doing most of the work.
By Jock Merriman, fifth-generation Merino woolgrower and founder of Sir W. Merino
Autumn is the season that exposes a wardrobe. In summer you wear less and in winter you wear more, and either way the decision is simple. Autumn gives you a morning that starts properly cold and an afternoon that forgets it was ever cold at all. You leave the house in a jacket, you take it off by lunch, and you put it back on for the drive home.
Most men solve this with the jacket. They buy a better one, or a lighter one, or one with a zip in the lining. I'd suggest the problem sits one layer lower, and that the shirt against your skin decides whether the day goes well.
Why does the layer under the jacket matter most?
Because it is the only layer that stays on all day. The jacket comes off. The shirt does not. Whatever it does with heat and moisture, it does for ten or twelve hours, through the cold start, the warm middle and the cooling evening.
A cotton shirt takes up sweat and holds it against you. Once the temperature drops again, that damp patch is the first thing you notice. A polyester shirt moves moisture quickly enough but is plastic, and it tends to trap odour long before the day is out. Neither was designed for a day that changes its mind.
What does Merino do differently across a day like that?
Wool is a protein fibre with a structure that takes up moisture vapour, up to about 30 percent of its own weight, before it feels damp to the touch. It holds that moisture inside the fibre rather than on the surface of your skin, and it releases it again as the air around you dries. That is why a Merino shirt can sit comfortably under a jacket at eight in the morning and still feel fine when the jacket is over a chair at two.
The crimp in the fibre also traps a thin layer of air, which is where the warmth comes from. When you warm up, that same structure lets heat and vapour move out. I won't pretend this is magic. It is a fibre doing what it evolved to do, which is keep a sheep comfortable on a hill where the weather changes without warning.
Boorowa, where my family has run Merryville Merino stud, sits up in the NSW tablelands. Frost in the morning and a warm afternoon are ordinary there. The sheep manage it in a fleece. The same fibre, grown finer, works in a shirt.
What should you look for in the shirt?
Three things, in order.
Fineness. A shirt worn all day against the skin needs to be soft. Our fabric is superfine Merino in the 17.5 to 19 micron range, well under the roughly 30 micron point where wool begins to prickle most people. Fineness is about comfort, not warmth. I would not claim Merino is finer than good cotton, because it isn't. What it does is behave better.
A cut that tucks or hangs cleanly. Under a jacket, a shirt that bunches is a shirt you'll fidget with. The Bruce is a button-up, which gives you a collar and a line that sits correctly under a blazer. The George, named after my father, is the polo I'd choose when the jacket is a casual one.
Enough fabric to be worn twice before it needs a wash. This is where the fibre earns its keep. Wool's resistance to odour comes from its structure and its keratin, not from anything added, and it means a shirt can be aired overnight and worn again. It saves washing, and washing is what ages clothes.
What does that look like on an ordinary autumn weekday?
You put on a Merino button-up at seven. You wear a jacket to the car, the office and a late meeting. At one o'clock the room is warm and the jacket is on the back of the chair, and the shirt looks the way a shirt should look at one o'clock. At six you put the jacket on again. You hang the shirt up, it airs overnight, and you wear it again tomorrow.
That's the whole case. There's no trick in it, and nothing here is a reason to buy more shirts. It's a reason to own fewer, better ones.
An honest caveat
Merino is a base layer, not a coat. On a properly cold day you still need the coat. And a close-fitting shirt will sit closer than a loose cotton one, so check the size chart before ordering. One verified customer told us the same about The Bruce and he was right.
Bottom line
Autumn is hardest on the layer you forget to think about. Choose the shirt against your skin for what it does at eight in the morning, at two in the afternoon and again at six, and the jacket takes care of itself.
Frequently asked questions
Is Merino too warm to wear under a jacket?
Not in a fine, lightweight knit. The fibre takes up moisture vapour and lets heat move out as you warm up, so it manages a warm office better than most people expect. In genuinely hot weather you will still feel the heat, as you would in any shirt.
Can I wear a Merino button-up under a blazer?
Yes. A button-up with a collar sits correctly under a blazer, and the fabric drapes without clinging. Check the fit first, as it runs close.
How many times can I wear a Merino shirt between washes?
It depends on the day, but because wool resists odour by structure, many people wear a shirt more than once between washes. Air it overnight and use your nose as the test.
Is Merino itchy against the skin?
Coarse wool can be. Superfine Merino in the 17.5 to 19 micron range is well below the roughly 30 micron threshold where most people feel prickle, though people with very sensitive skin should still test it.
Which Sir W. shirt is best for autumn layering?
The Bruce if the jacket is formal, The George if it is casual, and The Cassius tee as a base layer on cooler mornings.
— Jock Merriman, Founder · 5th generation
Jock Merriman is a fifth-generation Australian Merino woolgrower. His family has grown Merino since 1880 and runs the Merryville stud in Boorowa, NSW, founded by his great-grandfather Sir Walter Merriman. He started Sir W. Merino in Austin, Texas, and packs every order himself. Grown in Australia. Designed in Austin. Worn everywhere.
