Colored streaks on a piece of filter paper used for chromatography. Chromatography is a way of separating mixtures into molecules of similar size. In this case the mixture is a dye. A spot of dye is placed on the filter paper, the end of which is then stood in a shallow pool of a solvent, such as water. As the solvent absorbs up the paper it carries the components of the dye with it.Different components travel at different speeds, resulting in the multicolored streaks seen here.