The wet spinning.

Flax has been grown and spun in the north of Ireland for centuries, but the reason Irish linen came to mean fine linen is a piece of machinery. In 1825 James Kay found that drawing the flax through warm water before it reached the spindle softened what held the fibres together and let a far finer yarn be pulled from the same plant. Within a few years the wet-spinning mills had gone up across Ulster, and the trade settled there and stayed.

The shirt is woven from that yarn at 165 grams in a plain weave, and piece-dyed rather than yarn-dyed, so the colour sits in the finished cloth rather than in the thread it was made from. It is a summer weight, which is the only weight worth making a linen shirt in.

Nothing is put on it afterwards. Linen sold as easy-care carries a resin finish, which works by cross-linking the cellulose chains inside the fibre so they can no longer slide past one another. That is what stops it creasing. It is also what stops it softening, because the softening is that same movement happening slowly over years. A cloth held still chemically cannot break in.

So this one creases. It is marked at the elbow by the afternoon and soft at the collar and the cuff before the first summer is out, and it keeps going after that, until the cloth that arrived crisp is the one that feels like nothing at all. The finish would have bought a tidier first year at the price of every year after it, which is not a close call.