A plastics tool formed from a casting resin and having a working face which comprises a pre-formed metal sheet. The pre-formed metal surface may be of any derived metal such as aluminium, steel, stainless steel, galvanised steel, custom textured sheet or copper. The tool can be used in vacuum moulding. Holes are drilled through the metal sheet. The inner of the mould could be a porous mixture of, for example, an epoxy casing resin and an aluminium granulate. The porous layer is surrounded by an impervious covering through which it is attached to a vacuum line, thereby forming a vacuum mould. The mould tool can also comprise heating or cooling tubes.