Shrinky dinky crispy

Today we were inspired to make something I made as a young child myself. I had to check online that it was still possible with today's packaging but it is.
To shrink your crisp packet into a very small and harder version of itself all you need to do is;-
Eat some crisps
Ensure the empty packet has silver on the inside
Make it as flat as possible (over night is a stack of books would probably be ideal - we needed immediate satisfaction so didn't really get it flat enough to keep it's shape very well)
Lay the crisp packet on a piece of aluminium foil and fold the foil over the top and make a flat envelope
Heat the oven to 200*c
Put the silver envelope in the oven on a baking tray
Leave for exactly 3 minutes
Remove, let cool and unwrap from it's envelope - It is like Magic (if you are 3!)