Abstract: A coating is applied to a substrate using an intermediate membrane. The coating is typically conductive or semiconducting, and the substrate is typically glass. In one form, the coating is applied, in one or more layers, to a flat flexible membrane. The membrane is then placed on the substrate, and the combination is treated under controlled conditions in a heating chamber. The combination is first heated in a neutral atmosphere to cause volatisation of the sacrificial membrane, then successively in oxidising and reducing conditions to cause strong bonding between the coating and the substrate. In another form, a non-sacrificial membrane has a substrate contact surface which is physically and chemically compatible with the substrate and which, when treated either chemically or thermally, forms a bond with the substrate.