Superforming is a hot metal forming process that uses similar principles to thermoforming plastics, where a sheet of material is heated and forced onto a male or female form using gas pressure. The process is useful for producing complex surfaces. The technique was pioneered for use in alloy fighter jets, with a sheet of aluminum heated like "taffy" and then "blown" into a mold by a press system, allowing complex curves. It heats the sheets to 500 degrees Celsius, and after molding, vacuums out the air.