Scratch and sniff

Today Clover asked what was up with “scratch and sniff”. So we looked into them!

Turns out, you capture aroma particles in tiny bubbles in a process call microencapsulation, and then they break apart when gently rubbed.

Here’s a funny point:

Scratch-and-sniff stickers and labels became popular in the late 1970s, and remained so through to the mid-1980s. In 1977, Creative Teaching Press produced some of the earliest scratch and sniff stickers. These stickers were mainly marketed to teachers as rewards for their students.[2]

Well, now I know why everyone I grew up with knows about these things.

Utility companies have enclosed scratch and sniff cards in their bills to educate the public in recognizing the smell of a methane gas leak. In 1987, cards distributed by the Baltimore Gas and Electric Company led to a rash of false alarms when the scents of cards in unopened envelopes were mistaken for real gas leaks.[3]