A method of shaping a surface of a workpiece comprising the steps of: measuring the workpiece to obtain measurement data of the surface (S) to be shaped; comparing the obtained measurement data with data representing the required form of the said surface of the workpiece, to determine an amount and distribution of material to be removed; analysing the data representing the required surface form of the workpiece surface to determine form characteristics of the surface (S) to be shaped; providing a shaping tool of a size and form which can treat all parts of the surface (S) to be shaped on the basis of the determined form characteristics; determining a tool path for moving the shaping tool over the surface (S) to be shaped in order to remove the material from the surface (S), wherein the tool path defines a tool offset at all points along the tool path, the tool offset being the amount of a deformation of the tool against the workpiece surface (S); and shaping the workpiece by mounting a shaping tool having the determined size and form in a fixture , and moving the shaping tool over the said surface (S) of the workpiece surface using the determined tool path in order to remove the material from the workpiece surface (S), wherein the tool offset at all points along the tool path does not exceed a maximum tool offset and wherein the maximum tool offset is such that the shaping of the workpiece remains within a ductile regime at all points along the tool path; wherein either the shaping tool has an abrasive working surface or, during the shaping of the workpiece, an abrasive slurry is provided between the shaping tool and the workpiece. measuring the workpiece to obtain measurement data of the surface (S) to be shaped; comparing the obtained measurement data with data representing the required form of the said surface of the workpiece, to determine an amount and distribution of material to be removed; analysing the data representing the required surface form of the workpiece surface to determine form characteristics of the surface (S) to be shaped; providing a shaping tool of a size and form which can treat all parts of the surface (S) to be shaped on the basis of the determined form characteristics; determining a tool path for moving the shaping tool over the surface (S) to be shaped in order to remove the material from the surface (S), wherein the tool path defines a tool offset at all points along the tool path, the tool offset being the amount of a deformation of the tool against the workpiece surface (S); and shaping the workpiece by mounting a shaping tool having the determined size and form in a fixture , and moving the shaping tool over the said surface (S) of the workpiece surface using the determined tool path in order to remove the material from the workpiece surface (S), wherein the tool offset at all points along the tool path does not exceed a maximum tool offset and wherein the maximum tool offset is such that the shaping of the workpiece remains within a ductile regime at all points along the tool path; wherein either the shaping tool has an abrasive working surface or, during the shaping of the workpiece, an abrasive slurry is provided between the shaping tool and the workpiece. <EOS>