Two-Ply (2-Ply) Yarn

Two-ply (or double-ply) fabric is woven from yarns made by twisting two single strands together, versus single-ply’s one. Plying makes a stronger, smoother, more durable and often finer fabric that resists wear and holds a press — which is why "two-ply" is a common marker on better dress shirts. You will also see thread-count-style claims like "100s two-ply," where the number is yarn fineness. It is a real durability and hand upgrade, though, like all yarn specs, it describes the cloth and not the sewing; construction still decides the finished shirt.