The Millwheel Shirt is formed around the idea of rotational symmetry. The front chest pocket is tucked into the outward-facing button placket, as with the Butterfly Shirt, but on one side only. The under placket is sewn inwards, and the back pleat is taken out in one direction only (rather than a more usual symmetrical box pleat).

The direction of the back pleat and the front pocket line up when rotated around the centre axis of the shirt, like the blades of a millwheel.The sleeves are pleated into false cuffs, and the hem is finished in a gentle curve.