This paper gives an overview of sheet metal forming by liquid pressurized media separated from the sheet by membranes. The advantages and drawbacks in comparison with other sheet metal forming methods are shown. The boundary conditions for the choice of the membranes are discussed. The process window is determined by diVerent failure modes of wrinkles and fractures. It can be determined by ®nite element method (FEM) calculations, which is nowadays a precondition for the use of the process in production. The forming results show high limiting drawing ratios of more than 3 and a sound working accuracy. The integration of diVerent processes such as drawing and cutting into one step or the use of structured blanks makes shorter process chains possible.