The method of polymerization includes the steps of a) providing a catalyst system, b) providing at least one monomer or comonomer mixture in a reaction vessel, c) introducing the catalyst into the reaction vessel, and d) polymerizing the at least one monomer or comonomer mixture to produce an isoolefin polymer. The catalyst may be soluble in the diluent used for polymerization. The polymerization contact surfaces of the reaction vessel have an arithmetic average surface roughness of less than 0.3 μm (12 microinches).