Two-ply shirting, explained

The shirting book is the newest thing on the shelf and the only cotton we hold. Sixty colours, plain and patterned, all of it two-ply. That last word is the one worth understanding, because it is the difference between a shirt that lasts two years and one that lasts six.

What two-ply means

A yarn is spun from short cotton fibres held together by twist alone. Pull at a single yarn and the ends work loose. Two-ply is two finer yarns twisted around each other before the cloth is woven, so each one holds the other closed.

The result is smoother to the hand, holds a press for longer, and frays far more slowly at the collar and the cuff, which is where a shirt actually dies.

And what the weight means

This book runs from 100 to 150 grams per square metre. Suiting starts at 270 and most of ours is 360, so a shirt is between a third and a half the weight of the jacket that goes over it.

In practice the lighter end is what you want under a jacket in April. It moves air, it dries quickly, and it does not add a layer of warmth you cannot take off. The heavier end holds a collar better and looks crisper across a desk. What you actually feel between the two is mostly the weave rather than the weight.

Choosing between sixty

Start with what the shirt is for. A plain white or a pale blue works under every jacket you own and is the shirt to order first. Stripes and checks are second shirts: they are lovely, and they are also a decision you have to make again every morning.

Then hold two candidates against the suit cloth rather than against each other. A shirt is only ever seen next to a jacket and a collar, and a colour that wins on the table can lose completely at the neck.