From the Science in a Box booklet.
You’ll need: Paper towel, A cup of water, Food colouring
Cut the paper towel into fun shapes (triangle, square, diamond, or into the shape of a doll)
Add a few drops of food colouring to the water.
Touch the very bottom of the paper towel shape to the surface of the water. (With paper dolls, you can make each pant leg a different colour if each foot is in different-coloured water!)
Hold it there for several minutes. What do you notice?
What is happening? Like all materials made of natural fibres, Paper towel has spaces that form tiny capillary tubes.