There is a cotton that everyone uses for sleepwear because it is cheap, and there is a cotton that the brands you actually trust use because it lasts. Premium compact cotton is the second kind.
What it is
It starts as 100% cotton — no synthetic blend, no modal. The difference is in the spinning. "Compact" cotton is combed to remove the short, stray fibres and then compact-spun, which twists the remaining long fibres into a smoother, denser, stronger yarn. Fewer stray fibres on the surface means less fuzz, less pilling, and a cleaner hand that stays soft instead of going rough. You get the breathability of pure cotton with a finish that holds up wash after wash.
How to wash it so it lasts
Cold water, gentle cycle, hang dry. Do not use fabric softener — it coats the fibres and dulls the cotton over time. Tumble drying on high is the fastest way to make any soft fabric pill. Treated this way, a T&D Set should look the same after fifty wears as it did out of the bag.