Supercritical fluid chromatography (SFC) offers several advantages to chromatographers including the “green” aspect of using carbon dioxide as a mobile phase, the ease of isolation of purified components from preparative separations, and decreased analysis times because of the high diffusivity and low resistance to mass transfer encountered in SFC. Using a molecular diversity model to choose test probes from a chemical library, the authors characterized 12 SFC achiral stationary phases with 60 compounds from four chemical classes – amines, amides, alcohols, and carboxylic acids – to establish guidelines for the rational selection of the optimum stationary phase for separations. Efficiency, selectivity, and peak shape were used as the evaluation criteria.