A method of preparing an ion-conducting polymeric material, for example, for a fuel cell, in a desired form (hereinafter "said formed polymeric material"), comprises: (i) selecting a first ion-conducting polymeric material; (ii) selecting a solvent formulation which can dissolve said first ion-conducting polymeric material, wherein said formulation includes a first solvent part which is water; (iii) preparing a composite formulation in a process which includes dissolving first ion-conducting polymeric material in said solvent formulation; (iv) forming said composite formulation into a desired form; (v) providing conditions for removal of said solvent formulation from said form described in (iv) thereby to prepare said formed polymeric material. The first ion-conducting polymeric material preferably includes polyaryletherketone units. Said solvent formulation preferably includes a second solvent part selected from acetone, tetrahydrofuran and acetone.