Effect pigments based on artificially produced substrates with a narrow size distribution

Effect pigments consisting essentially of artificial platelet-shaped substrates which have only one optically active coating comprising TiO2 in the rutile or anatase crystal polymorph, wherein in case of the rutile polymorph, the coating is obtained by a process comprising applying SnO2 to the substrates, applying TiO2 to the applied SnO2, and then calcining the substrates, wherein the effect pigments have a volume-averaged cumulative undersize distribution curve with the characteristic numbers D10, D50 and D90, said cumulative undersize distribution curve having a span ΔD of 0.7-1.4, and the span ΔD being calculated in accordance with formula (I):

• ΔD=(D90−D10)/D50 (I),
• and the average thickness of the artificial platelet-shaped substrates being 500 nm to 2000 nm, wherein the standard deviation of the thickness of the artificial platelet-shaped substrates is 15% to 100%, and wherein the artificial platelet-shaped substrates are substantially transparent and are selected from the group consisting of glass platelets, platelets of synthetic mica, SiO2 platelets, platelet-shaped bismuth oxychloride, platelet-shaped aluminum oxides, and mixtures thereof.