A method for manufacturing a metal coated substrate by forming a metal coating on a surface of a substrate, wherein the metal coated substrate is for applications that require concealed illumination systems, image recording systems, sensors or radar antennas, comprising the following steps: a) carrying out a sensitization step by: - immersing the substrate in a colloidal palladium/tin colloidal solution; - immersing the substrate in a tin aqueous solution and, thereafter, in a palladium aqueous solution, or vice versa; or - depositing on the substrate a silver nucleus by immersion or a spray method; b) immersing the substrate in an acid solution; c) optionally, immersing the substrate in a PdCI solution; d) carrying out electroless metal plating by immersing the substrate in a nickel electrolyte solution to form a metal coating on the surface of the substrate in order to obtain a continuous film-coated substrate, wherein the metal electrolyte solution comprises a source of nickel cations, a complexing agent and a reducing agent which is a hypophosphite alkali metal salt, characterised in that the sensitization step is carried out for 12 to 17 min and either in that electroless plating is carried out for 5 to 20 seconds at a temperature from 65 to 75 °C at a pH of 6 to 7 in order to obtain a coating with a phosphorus content from 1 to 4 wt% related to the total weight coating, or in that electroless plating is carried out for 15 to 60 seconds at a temperature from 40 to 60 °C at a pH of 8 to 10 in order to obtain a coating with a phosphorus content from 10 to 25 wt%, particularly from 10 to 14 wt%, related to the total weight coating. a) carrying out a sensitization step by: - immersing the substrate in a colloidal palladium/tin colloidal solution; - immersing the substrate in a tin aqueous solution and, thereafter, in a palladium aqueous solution, or vice versa; or - depositing on the substrate a silver nucleus by immersion or a spray method; - immersing the substrate in a colloidal palladium/tin colloidal solution; - immersing the substrate in a tin aqueous solution and, thereafter, in a palladium aqueous solution, or vice versa; or - depositing on the substrate a silver nucleus by immersion or a spray method; b) immersing the substrate in an acid solution; c) optionally, immersing the substrate in a PdCI solution; d) carrying out electroless metal plating by immersing the substrate in a nickel electrolyte solution to form a metal coating on the surface of the substrate in order to obtain a continuous film-coated substrate, wherein the metal electrolyte solution comprises a source of nickel cations, a complexing agent and a reducing agent which is a hypophosphite alkali metal salt, the sensitization step is carried out for 12 to 17 min and either in that electroless plating is carried out for 5 to 20 seconds at a temperature from 65 to 75 °C at a pH of 6 to 7 in order to obtain a coating with a phosphorus content from 1 to 4 wt% related to the total weight coating, or in that electroless plating is carried out for 15 to 60 seconds at a temperature from 40 to 60 °C at a pH of 8 to 10 in order to obtain a coating with a phosphorus content from 10 to 25 wt%, particularly from 10 to 14 wt%, related to the total weight coating.