A telecommunications conductor is produced by coating it with a visco-elastic dielectric material and then providing an electrically conductive material around the conductor by bombarding the visco-elastic material with particles of the conductor material and changing the visco-elastic material into hardened form. A shielding layer is provided by causing the particles to adhere to the surface of the dielectric material and when the particles provide a conductive path, the layer is completed by applying conductive material by electrolytical deposition or by plasma coating. Alternatively in an insulated conductor provided with a continuous inductive loading, the particles are caused to enter into and become discretely embedded within the visco-elastic material.