The superplastic forming of suitable metal alloy sheets into strong components, such as automobile body structures or panels, is improved and accomplished faster by simultaneously forming two or more substantially identical, relatively thin sheets, preferably about 2 mm or less in thickness, rather than a single sheet of the same overall thickness. For example, two or more layers of thin AA5083 sheets can be stretched formed together at about 500° C. with greater deformation and elongation than a single sheet of comparable thickness.