A method of forming a component (30) by isostatic pressing, the method comprising: providing a canister (4) suitable for isostatic pressing, the canister comprising first and second membranes (14, 16) which, in use, are disposed within the canister (4); the first and second membranes (14, 16) defining a component cavity (24) disposed between the first and second membranes (14, 16), a first tool cavity (26) disposed between the first membrane (14) and an adjacent wall (10) of the canister (4), and a second tool cavity (28) disposed between the second membrane (16) and another adjacent wall (12) of the canister (4); filling the component cavity (24) with the component powder for forming the component (30); filling the first and second tool cavities (26, 28) with a second tool powder; and isostatically pressing the canister (4) to form the component (30).