How we can help Resource Library Magic Gloop! This activity is really easy to do and is a great way of showing kids the differences between solids and liquids - it's great for adults too! What you'll need: Cornflour Water Food colouring (optional) Waterproof dish Add about half a bag of cornflour to the dish. Add water slowly until you reach a firm but runny consistency, then add food colouring if using. Watch as the gloop is firm when you move it around but runs through your fingers as you hold it still. *This activity is easy to do but can be quite messy, so make sure you have old clothes on and you do this on an easy clean surface. The gloop will wash away and dissolve in water.