Abstract The separation of polar compounds, based on using the whole upper section of the “prisma” model for mobile phase optimization, is described. The solvent combinations in normal-phase chromatography possible with the upper part of the model are discussed. Rules for the selection of the solvents that form the prism are given, together with the final optimization strategy for overpressured layer chromatography separations. Depending on the separation problem, optimization of the mobile phase can be accomplished with or without a modifier to increase the solvent strength and/or eliminate the tailing effect. The separation of ginsenosides is discussed as an example of the application of the model without modifier. The separation of the flavonoid glycosides from Betulae folium demonstrates the use of the upper section of the prism with a modifier for mobile phase optimization.