TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The opening diameter of the exit of the liquid spray nozzle is less than 1 mm. The liquid spray nozzle is designed so as to be capable of generating an aerosol having a mean droplet size of 0.5-100 mu m.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The plasma jet is generated by a plasma nozzle (4) having a nozzle exit (5), and the liquid comprises the hybrid inorganic-organic pre-polymers is injected in the plasma jet after leaving the nozzle exit and prior to impinging on the surface of the substrate. The liquid comprising the hybrid inorganic-organic pre-polymers is injected in the plasma jet through a liquid spray nozzle, preferably in the form of an aerosol. The distance (d) along a parallel to the central axis of the plasma nozzle between the exit of the liquid spray nozzle and the nozzle exit of the plasma nozzle is 2-30 mm, preferably 5-15 mm. The method comprises applying liquid comprising hybrid inorganic-organic pre-polymers on a surface of the substrate and exposing the surface to cure the hybrid inorganic-organic pre-polymers to give inorganic-organic hybrid polymer material. The plasma jet used in step (ii) is generated by a plasma nozzle and the substrate with the applied liquid is scanned with the plasma nozzle. The distance (g) along a parallel to the central axis of the plasma nozzle between the nozzle exit of the plasma nozzle and the substrate is 3-40 mm, preferably 3-20 mm. The hybrid inorganic-organic pre-polymers are obtainable by hydrolytic condensation of at least one hydrolytically condensable compounds of silicon and optionally other elements including boron, aluminum, phosphorus, tin, lead, transition metals, lanthanides, and actinides, and/or their precondensates, where 10-100 mol%, in terms of monomeric compounds of the hydrolytically condensable compounds are silanes of formula (SiXaR14-a) (I).R1 = alkyl, alkenyl, aryl, alkylaryl or arylalkyl having 1-50C (all optionally substituted);X = H, halo, OH, alkoxy, acyloxy, alkylcarbonyl, alkoxycarbonyl or NR2;R2 = H, alkyl or aryl; anda = 1-3.Preferred Components: The substrate is a polyethylene-terephthalate substrate and where the coated substrate has a substrate thickness of 23 mu m and an oxygen transmission of less than 5 cm3/(m2d bar). EXAMPLE - A plasma coating apparatus was used, in which the liquid spray nozzle was arranged in a horizontal distance (f) of 20 mm with respect to the central axis of the plasma nozzle, and at a distance (d) to the nozzle exit of the plasma nozzle along a parallel to the central axis of the plasma nozzle of 10 mm. The liquid spray nozzle was made of glass, and the exit of the liquid spray nozzle had an opening diameter of 400 mu m. An aerosol of an ORMOCER (RTM: Inorganic-organic hybrid polymers) liquid was generated by mixing the liquid with nitrogen as a carrier gas. Thus the created aerosol was sprayed in the plasma jet through the liquid spray nozzle. A polycarbonate plate was used as a substrate. The substrate was moved at a velocity of 10 m/minutes through the plasma jet. The distance (g) between the substrate surface and the nozzle exit was 20 mm.