Shrinky Dinks were sooooooo kewl when I was young !

Shrinky Dinks are a children's toy/activity kit consisting of large flexible sheets which, when heated in an oven, shrink to small hard plates without altering their color or shape. They reached the height of their popularity in the 1980s. Most sets are pre-printed with outline images of popular children's characters or other subjects, which are then colored in before baking.
And did you also "shrink" chip packets in the oven to... before they became foil ?

Fuzzy Felt..