In this chemistry activity, learners use thin layer chromatography to determine the molecular composition of different markers. First, they use pure rubbing alcohol as the liquid phase, then experiment with mixtures of alcohol and water to see which works best. Different black markers can be tried to see how their components compare. A quantitative measure of the "retention factor" is calculated to relate the distance traveled by the spot to the distance traveled by the mobile phase. A later experiment has learners try to identify an unknown ink sample by comparing it to known samples, and then opens it up to artistic pattern-making using chromatography and markers. The activity is written to be part of a kit, but the kit is not required.