A careful selection of the chromatographic sorption milieu can make possible the classification of organic pigments without use of comparative substances. Azo pigments can be identified by normal thin-layer chroma-tography with non-polar flow media on oxidic carrier materials. Phthalo-cyanine pigments are distinguished in that they do not flow in any of the applied procedures of thin-layer chromatography. The substantivity of pigments can be tested by reaction chromatography. -- AATA