Abstract: A method of making an optically black surface having a low reflectance of electromagnetic radiation, especially in the solar spectrum, a relatively high heat resistance, and a relatively low amount of off-gassing, comprising the steps of(a) Milling the following mixture of ingredients for up to about 50 minutes:______________________________________ Ingredient Amount (% by weight) ______________________________________ Alkali metal silicate 13-21 Internal cure agent 2-10 Black pigment 17-27 Mica 0-3 Water 50-70 ______________________________________wherein the internal cure agent is selected from the group consisting of CuO, Cu.sub.2 S, NiO .multidot.Ni.sub.2 O.sub.3 and Co.sub.2 O.sub.3.

Abstract: A method of making an optically black surface having a low reflectance of electromagnetic radiation, especially in the solar spectrum, a relatively high heat resistance, and a relatively low amount of off-gassing and an optically black surface made by the method which includes the steps of(a) Milling the following mixture of ingredients for up to about 25 minutes:______________________________________ Ingredient Amount (% by weight) ______________________________________ Alkali metal silicate 13-21 Black pigment 17-27 Kaolin 0-5 Mica 0-3 Water 50-70 ______________________________________(b) Coating the surface to be rendered optically black(1) by applying at least four or five coats of an inorganic composition comprised primarily of an alkali metal silicate and pigment, and(2) by spraying at least the last two surface coatings, and having them comprise the above milled mixture, and(c) Drying at least the coats prior to the last two coats, before applying the last two coats.