This document discusses the technique of paper chromatography. It was introduced in 1906 by Dr. M. Tswett and is a simple separation method based on the principle of partition chromatography. There are several types of paper chromatography including ascending, descending, ascending-descending, radial, and two-dimensional. Paper chromatography has many applications such as identifying components in mixtures, analyzing drugs and impurities, and separating colored mixtures. It is a basic but inexpensive and rapid analytical chemistry technique commonly used in pharmaceutical and chemical industries.