History of Planar Chromatography.- The Theoretical Basis of Thin-Layer Chromatography (TLC).- The Stationary Phase in Thin Layer Chromatography (TLC).- The Mobile Phase in Adsorption and Partition Chromatography.- Preparing and Applying Samples.- Basis for TLC Development Techniques.- Specific Staining Reactions.- Bioeffective-linked Analysis in Modern HPTLC.- Planar Chromatography Detectors.- Diffuse Reflectance from TLC Layers.- Fluorescence in TLC Layers.- Chemometrics in HPTLC.- Reciprocal Model.- Statistics for Quantitative TLC.- Planning an Analysis and Validation in TLC.