Learners analyze mixtures of dyes using filter paper chromatography. They place spots of the different dyes at the bottom of a piece of filter paper, and hang the paper to touch the surface of water. As water climbs the paper, the dye mixture travels with the water and indvidual dyes separate. Different dyes can be separated according to their solubility and size. The original operating procedure gives instructions for making mixtures of common laboratory dyes. However, water soluble markers of various brands also work well. This activity is currently used in the Biochemistry Unit in OMSI's Chemistry Lab. Cost estimates are per 100 learners.