A friend of mine showed me how to make these a long time ago. Recently I found the shrinky dink chip bag he gave me and I decided to try making my own. Except I wanted to make something cool with them. I came up with the idea of making key chains out of them.
First of all, I want to start by saying DO THIS PROJECT AT YOUR OWN RISK. It involves putting things in the microwave that you really shouldn't. This will make sparks in your microwave and could be potentially unsafe or harmful to yourself or your microwave and I can't be held responsible for any accidents. That being said, I have made half a dozen of these in my own microwave with no injuries and my microwave still works just fine. Just use caution and your own judgment.
Start with some mini snack-sized chip bags.
Cut a hole at least the size of a quarter near the top or the corner. Be sure not to cut the hole too close to the edge. Remember, these are going to shrink quite a bit, so leave plenty of room around the edge.
Place the bag in the microwave (only one at a time). Turn the microwave on, but don't walk away. This will take literally 5 seconds. And, as I said, it will cause sparks, but it will quickly shrink the chip bag down right before your eyes. Be ready to open the microwave door quickly. Carefully remove the bag from the microwave. You may even want to leave it in there for a minute or two. It will still be very hot. It takes about 5 minutes for the bag to cool and harden.
Wait until they have hardened completely, then thread a keyring through the hole you made. Voila! You have a cool key chain or zipper pull to always remind you of your favorite chips! I think this is a project kids would enjoy (with supervision of course), especially 8-10 year old boys.