Abstract: A method of forming a device of composite material includes providing a mold having an internal space forming a cavity with an inner surface, the cavity having a shape corresponding to an inner shape of the device to be formed, placing inserts at one or more pre-defined positions along the inner surface, holding the inserts at the one or more positions, introducing removable material into the cavity of the mold to form a pattern having the inserts fixed therein when the removable material is in solid form, and removing the pattern having the inserts fixed therein from the mold.