What was the original 'failed' product that eventually led to the invention of Post-it Notes at 3M?

The path to groundbreaking inventions isn't always straightforward! Some of the world's most useful products emerged from unexpected places or even from what seemed like failures. The Post-it Note is one such invention that revolutionized how we organize information, leave messages, and mark pages. Behind this simple adhesive paper lies a fascinating story of accidental discovery and persistent product innovation.

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A super-strong adhesive that was too powerful for commercial use
A weak adhesive originally intended for aerospace applications
A waterproof paper that couldn't hold ink properly
A heat-resistant coating that kept detaching from surfaces