A shirt looks like a simple garment and then behaves completely differently depending on what it is cut from. Poplin is a tightly woven cotton with a smooth face that holds a crisp line and takes a press. Linen is loosely woven, breathes better than anything and creases as a matter of course. Silk and its modern substitutes drape rather than hold, which flatters but shows every mark. Choosing badly is why people own shirts they never wear rather than shirts they dislike.

Poplin is the only one of the three that reliably works under a fitted jacket, because it is thin, smooth and does not bunch at the armhole. Linen bulks up and creases where the jacket presses it. Silk slips against a lining and can ride up the arm all day. If you mostly wear a shirt alone, that reverses: linen is the most comfortable thing you can have on in heat, and silk looks considerably more expensive than it costs when nothing is covering it.

Poplin is the easiest: machine wash, hang damp, and most of the creasing falls out. Linen softens with every wash and looks better for it, which makes it the one fabric where age is an improvement. Silk needs cold water and no wringing, and the washable silks now on the market genuinely do survive a gentle machine cycle, though not a dryer. The synthetic satins that look like silk usually hold odour rather than releasing it, which is the practical reason to pay for the real thing or a modal blend instead.

If you take one thing away, buy poplin for anything you will wear under a jacket and linen for anything you will wear alone in heat, and stop trying to make one shirt do both. They are different garments that happen to share a shape. If you want a single top that goes furthest, a silk or modal camisole is quietly the most useful thing in this list: it works under a blazer, under a knit, or alone at dinner, and it takes up almost no room in a bag.