A mould for manufacturing a packing member from a liquid ceramic composition. The mould including a first part and a second part, wherein the first part and/or the second part comprise an open mould cavity and wherein the first and second parts are operable to engage to form a closed mould cavity, wherein the mould further includes a reservoir forming member, and wherein the mould is operable to be moved from an open position in which the first and second parts are at least partially spaced such that the reservoir member forms a reservoir cavity and the mould cavity is open, to a partially closed position in which the location of the reservoir cavity has moved with respect to the mould cavity and/or the volume of the reservoir cavity has reduced, and then to a closed position in which the first and second parts are engaged such that the mould cavity is closed.