Inorganic coatings comprising layer minerals

An inorganic coating for a substrate comprising a layer of lamellae of a layer mineral, preferably vermiculite, in which substantially all of the lamellae are of size below 50 microns, production of the coating by applying a suspension of the lamellae to the substrate and removing the liquid from the suspension, articles comprising a substrate having the coatings thereon and use of the coatings and the articles for the thermal insulation and fire protection of materials. The coating significantly upgrades the thermal insulation and fire performance of substrates even when only a few microns, for example below 50 microns and even below 10 microns, in thickness.