Seventeen solvents ranked by elution strength on silica and on alumina, and by polarity index. A mixture is placed on the same scale from its volume shares.
Give the Rf a spot ran to and the Rf wanted, and read the share of the strong solvent to try next. The range comes from the Snyder and Soczewiński relation.
Straighten a picture of a thin-layer chromatography plate, mark its spots and read every Rf value, then weigh its eluent on a solvent scale. The tool needs JavaScript, because the picture is read in your browser.