Superplastic forming of sheet metal enables forming of complicated details in one step. The forming is done at very low strain rates, making the process slow and cycle times very long. By shortening the cycle time, it should be possible to decrease the unit cost of production and, as a result, superplastic forming would be a highly competitive forming method for new areas of application. A number of methods to shorten the cycle time are presented. Materials considered were Al 7475, Supral 100, and Cr--Ni steel Avesta 223 FAL.