A net shaped latex vacuum bag as used in the fabrication of composite structural parts having complex shapes. Liquid latex is first allowed to air dry in the form of a thin flat, flexible sheet. The latex sheet is then vacuum formed over a tool having the complex shape of the part to be fabricated and assumes the shape and configuration of the tool's outer surface. The latex sheet is then rapidly cured at an elevated temperature, so as to permanently assume the part's shape for subsequent use in forming composite structural parts of the same complex shape. In one embodiment, the latex sheet may be formed on the tool by dipping the tool in liquid latex, allowing the latex coating to dry, and cutting the dry latex coating to permit separation of the tool from the latex coating which is then used in composite part fabrication.