In the 1960s, 3M chemist Dr. Spencer Silver set out to create a super-strong adhesive—and accidentally invented a weak one instead. It was tacky enough to stick but peeled off without a trace. Silver knew it had potential, even if no one else at 3M did.

Years later, his colleague Art Fry had a problem: his choir bookmarks kept slipping out of his hymnal. Remembering Silver’s “failed” glue, Fry had an idea—stick small bits of paper to the pages. Reusable, repositionable, and just sticky enough.

That clever fix became Post-it Notes. Launched nationally in 1980, they quickly stuck around—on desks, fridges, and to-do lists everywhere.