Preferred inorganic pigments are metal oxides or other metal compounds which are insoluble or sparingly soluble in water, in particular oxides of titanium (TiO2), zinc (ZnO), iron (e.g. Fe2O3), zirconium (ZrO2), silicon (SiO2), manganese (e.g. MnO), aluminium (Al2O3), cerium (e.g. Ce2O3), mixe