described are thin plane - parallel aluminum flakes illustrated in fig . 1 having a thickness of up to 200 nm and comprising an inner layer of oxidized aluminium having a thickness of 0 . 5 - 30 nm , a process for the manufacture thereof and the use thereof , e . g . in formulations , like paints , electrostatic coatings , printing inks , plastics materials , and cosmetics . surprisingly , due to the inner layer of oxidized aluminum the aluminum flakes have an improved shear stability as evidenced e . g . by the difference in lightness before and after shear stress .