Make watercolours at home! Baking Soda Vinegar Cornstarch Corn syrup Mixing bowl with spout Measuring Cups Whisk Food colouring Ice Cube tray Pour 1 cup of baking soda into bowl. Slowly pour 3/4 cup of vinegar (it will bubble and fizz, don't do it all at once!) When they've stopped bubbling, whisk the mixture. Add 2 tablespoons corn syrup. Add 1 cup cornstarch. Whisk the entire mixture until combined. Pour into ice trays. Colour each cube with food colouring. Allow to dry (up to 2 days).