How we cut a bias dress

Cut a dress on the true bias and you are working with cloth at its most willing: it stretches, drapes, and forgives almost nothing. The grain runs at forty-five degrees to the selvedge, which is why the fabric moves with the body instead of across it.

It is also why the finished dress is hung for three days before anyone touches the hem. Silk on the bias grows — as much as two centimetres, unevenly. Hem it on day one and by the time it reaches you the back will be longer than the front.

It is slower. It is also the difference between a dress that hangs correctly in year five and one that does not.