Sprays of different material compositions A and B are directed to form a layer of coincident deposition of both material compositions A and B. The deposition is controlled such that a gradient of the relevant proportion of material composition A to material composition B is produced across the deposited layer. The provision of a controllable gradient of the relative proportion of material composition A to material composition B across the deposited layer enables the physical properties of the deposit to alter gradually across the depth of the deposit. The spray deposition method is useful when producing a machine tool, mould or die.
