Application of electrical conductors to an electrically insulating substrate

A method of applying a pattern of electrical conductors to an electrically insulating substrate, the method comprising:

• (a) providing a flexible membrane having a pattern of grooves in a first surface of the membrane, the pattern corresponding at least partially to a desired pattern of electrical conductors to be applied to the substrate and the first surface of the membrane comprising a thermoplastic polymer and being sufficiently flexible to conform to the surface of the substrate upon application of a pressure;
• (b) loading into the grooves a transferable composition that includes, as composition components, particles of an electrically conductive material and a transferable adhesive, said loading being performed in one or more cycles such that on completion of the loading step the transferable 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) bringing the first surface of the membrane into contact with an electrically insulating surface of the substrate;
• and
• (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 electrically insulating substrate by virtue of the transferable adhesive in the composition and the membrane to remain attached to the substrate.