How Do Scratch-and-Sniff Stickers Give Off a Smell?

There is an interesting technology behind scratch-and-sniff stickers that make it all possible.

Popcorn, root beer, strawberry, and pizza are just some familiar smells we remember from scratch-and-sniff stickers as kids. But there is an interesting technology behind scratch and sniff stickers that makes it all possible, and it has even been used to entice adults into buying products based on their smell.

The smell from a scratch and sniff happens, …