Paper chromatography is a type of partition chromatography. Its principle is based on the continuous differential partitioning of components of a mixture between the stationary phase and the mobile phase.

In this technique, a special quality chromatography paper is used, which contains water trapped in it. This trapped water acts as the stationary phase. A strip of this paper spotted at the base with the mixture is suspended in a suitable solvent, which acts as the mobile phase.

The solvent rises up the paper by capillary action and flows over the spot. The paper selectively retains different components according to their differing partition in the two phases, leading to the separation of the mixture.