DIY Chromatography

What you need

• Kitchen towels
• Water
• Non-permanent coloured felt tip pens

Instructions

1. Draw a dot in the centre of the kitchen towel with a felt tip pen. Black works well, but you can experiment with other colours
2. Add a few drops of water to the dot

Results and Explanation

As the water spreads through the tissue, the coloured pigments that make up the ink separate out.



The differently coloured pigments are made up of different-sized molecules. This means that the water can carry them different distances across the paper.

These experiments have not been specifically safety tested for home use but we believe them to be safe if the instructions are followed. Adult supervision or direction is recommended as appropriate. All experiments are carried out at your own risk.