Chromotography

This is good for separating dissolved substances that have different colours, such as inks and plant dyes. It works because some of the coloured substances dissolve in the liquid better than others, so they travel further up the paper. This method can be used to find out which dyes make a ink. A spot of ink is put on a piece of paper and is placed in water which when the water travels up the paper it takes the dyes with it and each dye travels a certain distance because of its solubility.