We used www.wikihow.com to find an easy and practically free way to make a kite out of a plastic bag:
As much fun as it is to fly a kite, it’s even better when you’re flying a kite that you made yourself. With this simple kite-building method, you will be able to save some money on materials by recycling used plastic shopping bags. While very simple to make, a kite made from plastic will fly very high and you will get hours of entertainment from both making it and flying it.
