A paint which contains a multitude of extremely thin platelets having a large area/thickness ratio, which serve to greatly reduce permeability of the paint when applied and dried.The formulation comprising at least a filmogen, a pigment, and a multitude of chemically-treated platelets about one nanometer thick. The platelets being dispersed in the formulation so that after application and solidification of a coating of the paint the platelets form a barrier substantially impermeable to both liquids and gases.