Abstract: A process is proposed for producing a protective layer on workpieces made, for example, from carbon composite material, for use at temperatures above 1000.degree. C. In accordance with the invention, a comminuted solids mixture with refractory ceramic powder articles, e.g., of carbides, nitrides and/or silicides, preferably from groups III, IV and/or VIb of the periodic table, and with at least one compound of the general elemental composition Me.sub.x B.sub.z, where Me represents one of the elements Si, Al, Zr, Ti, Hf or Y, and x and z each represent a number from 1 to 6, and optionally, in addition, with at least one already formed glass with the following general oxidic composition: Al.sub.2 O.sub.3 --B.sub.2 O.sub.3 --SiO.sub.2 --RO, where RO represents MgO, CaO or BaO, is dispersed in a liquid carrier system, deposited on free surfaces of a workpiece, and heated together with the workpiece briefly with air access to a maximum temperature of 1200.degree. C.