| CPC B05D 5/063 (2013.01) [B05D 3/06 (2013.01); B05D 7/24 (2013.01); G21K 1/067 (2013.01)] | 15 Claims | 

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               1. A method for applying a carbon-based reflective overcoating on a grazing incidence optical unit, the optical unit comprising a substrate and a coating of a first material, the method comprising: treating the optical unit with a liquid solution containing at least one organic precursor material to cause an absorption of the precursor material on said coating, and forming said carbon-based reflective overcoating from the precursor material, wherein the optical unit comprises a monolithic shell of nickel and the first material is a high-density material chosen from the group consisting of gold, platinum, iridium, palladium, rhodium, ruthenium, chrome and nickel. 
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