A process for forming a catheter balloon includes subjecting a tubular parison in a mold to molding fluid pressure. The resulting catheter balloon includes a balloon portion having two ends and tubular leg portions extending from either end. The ends of the balloon portion are tapered to the tubular leg portions. The tapered ends have alternating elongate areas of greater and lesser resistance to deformation displaced circumferentially about the tapered ends. The elongate areas of greater and lesser resistance to deformation can include ridges which are either longitudinal or spiraled or rods imbedded in the body of the balloon. While in the mold, the tubular legs are drawn axially sufficiently to form permanent creases in the tapered ends. This drawing may be sufficient to cause the material of the tapered ends to exceed the yield strength, particularly with the balloon material in a malleable state.
