A method of applying a pattern of electrical conductors to an electrically insulating substrate, which method comprises: a) providing a flexible membrane having a layer made of a formable plastics polymer capable of being embossed or cast, wherein a first surface of the membrane has a pattern of grooves embossed or cast therein, the pattern corresponding at least partially to a desired pattern of electrical conductors to be applied to the substrate; b) loading into the grooves of the first surface of the membrane a composition that includes, as composition components, electrically conductive particles and an adhesive, said loading being performed in two or more filling cycle(s) such that on completion of loading the composition substantially fills the grooves, level with the first surface of the membrane, and parts of the first surface between the grooves are substantially devoid of the composition; c) contacting the membrane with the substrate with the first surface of the membrane facing the substrate; d) applying pressure to the membrane to cause the composition loaded into the grooves in the first surface of the membrane to adhere to the substrate; e) separating the membrane from the substrate to transfer the composition from the grooves in the first surface of the membrane to the substrate; and f) applying sufficient energy to sinter the electrically conductive particles and to render electrically conductive the pattern of composition transferred to the substrate from the grooves; wherein the membrane is flexible enough to conform to the surface of the substrate so as to permit sufficiently intimate contact with the surface of the substrate so as to enable transfer of the composition loaded into the grooves in step (b) onto the substrate in step (e) in the absence of any adhesive layer on the substrate. a) providing a flexible membrane having a layer made of a formable plastics polymer capable of being embossed or cast, wherein a first surface of the membrane has a pattern of grooves embossed or cast therein, the pattern corresponding at least partially to a desired pattern of electrical conductors to be applied to the substrate; b) loading into the grooves of the first surface of the membrane a composition that includes, as composition components, electrically conductive particles and an adhesive, said loading being performed in two or more filling cycle(s) such that on completion of loading the composition substantially fills the grooves, level with the first surface of the membrane, and parts of the first surface between the grooves are substantially devoid of the composition; c) contacting the membrane with the substrate with the first surface of the membrane facing the substrate; d) applying pressure to the membrane to cause the composition loaded into the grooves in the first surface of the membrane to adhere to the substrate; e) separating the membrane from the substrate to transfer the composition from the grooves in the first surface of the membrane to the substrate; and f) applying sufficient energy to sinter the electrically conductive particles and to render electrically conductive the pattern of composition transferred to the substrate from the grooves;