Reproduce beautiful, multicolour art patterns using paper chromatography! Various colour pigments that make up black inks can be separated using radial chromatography. The inks are spotted onto a filter-paper circle containing a paper “wick” in the center, and the wick is placed into a cup of water. As water seeps outward through the paper, the different colour pigments in the ink mixtures separate out in a circular or radial pattern, producing a brilliant, multicolour artistic effect. The challenge is to duplicate the pattern—to decide which pens were used and how they were applied to the paper.