The right fabric for a Toronto summer.

There is a companion piece to this one about Toronto winters, and the two problems are not mirror images. Winter is about weight and wind. Summer here is about humidity, which is a different enemy entirely, and the fabric that solves it is not the one most men reach for.

Lightweight is not the same as cool

This is the mistake, and almost everyone makes it. A man comes in wanting the lightest fabric in the book, on the reasonable theory that less fabric means less heat. Then he wears a super-150s through a July afternoon and cooks.

Weight and breathability are two different properties. A very fine, very tightly woven fabric can feel light in the hand and still sit against you like cling film, because there is nowhere for air to move through it. A slightly heavier fabric with an open weave will let a breeze pass and carry moisture off your back. In a Toronto August the second one wins, and it is not close.

What you want is air in the weave, not the absence of weight.

What Sam reaches for

High-twist worsted, often sold as fresco. The yarn is twisted hard before weaving, which leaves it springy, slightly rough in the hand, and full of tiny gaps. It breathes, it shrugs off creases, and it recovers overnight on a hanger. For a man buying one summer suit to work in, this is the answer nine times out of ten.

Open-weave hopsack. A basket weave with visible texture. Cooler than it looks, and forgiving at the end of a long day.

Linen, with an honest warning. Nothing is cooler. Nothing wrinkles faster. Linen creases the moment you sit down and those creases do not fall out, and if that will bother you by four in the afternoon, do not buy it. A linen and wool blend keeps most of the cool and loses most of the drama.

Tropical wool, around 7 to 9oz, woven loosely on purpose. The traditional answer, and still a good one.

The part that sits under the fabric

You can choose perfectly and still be miserable, because the suiting is only the outer layer. A jacket lined in polyester has a plastic sheet stitched inside it, and no weave on earth breathes through that.

It is the most common reason a summer suit fails, and it has nothing to do with the fabric anyone chose. Worth knowing what is inside a jacket before spending anything on what is outside it: what a lining actually does, and why cupro is not a small detail.

For a suit that only comes out in July and August, ask about half-lining: lined through the shoulders and upper back, left open below. It hangs softer and wears far cooler, and the only real cost is that the inside has to be tidy enough to be seen.

Colour, and the thing nobody mentions

Dark fabric absorbs heat, which is true and worth knowing: mid-greys and soft blues do wear cooler than charcoal in direct sun. The more useful observation is about contrast. A lighter fabric hides what a dark one puts on display across the back at an outdoor wedding. For a summer wedding that is the practical argument for grey, and a better one than any rule about formality.

More on the whole year in fabric for Toronto seasons, or see the families side by side in the fabric library.

If it is for a wedding

Come earlier than you think. Not because making takes longer in summer, it does not, but because the good summer fabrics move in spring and the choice in June is whatever was left in May. Grooms planning an outdoor day should read the wedding pages, then come in and put a hand on a fresco. The difference between that and a smooth worsted registers in about two seconds and you do not forget it.