Abstract: The process is characterised in that it comprises at least one sol-gel layer with a maximum thickness of 800 nm, where said sol-gel layer comprises nanoparticles with a laminar crystal structure, and where each sol-gel layer is obtained from a silicon alkoxide solution; preparation of a dispersion that comprises at least one type of particles with a spherical, fibrillar or laminar morphology, and a laminar crystal structure, wherein at least one of the dimensions, thickness or diameter, of said particles is less than 400 nm; addition of the dispersion prepared to the solution; deposition of the suspension on said substrate; thermal treatment of the substrate; and, in the case of multilayer coatings, optionally, the addition of high-dimensional particles and repetition of the steps, provided that the thermal treatment of the last layer, or outer layer, is performed at a temperature equal to or greater than that of the preceding layer. The invention also relates to the sol-gel coating thus obtained.