Marker ink is made by mixing different pigments together. These pigments are made of different chemicals that are heavier or lighter than each other. Paper chromatography is a technique used to separate mixtures. In this case, as the water moves through the ink, we can see the different speeds that the different pigments travel. Heavier pigments move slowly and will separate out first. Lighter pigments move faster and will move further up the coffee filter. This difference allows us to see the separation of the different pigments in one marker.