Which accidental discovery led to the invention of Post-it Notes at 3M in the 1970s?

Product design has transformed human history through ingenious solutions to everyday problems. Some designs were so revolutionary they changed entire industries and the way we live. This poll tests your knowledge about a famous product design breakthrough that resulted from accidental discovery but became one of the most successful office supplies in history. Can you identify the correct origin story?

This is a live public trivia poll on AIPolls.Net. Vote and see real-time results.

A weak adhesive that Spencer Silver created while trying to develop a super-strong glue, which failed its original purpose but was perfect for removable notes
A temperature-sensitive dye that changed colors when touched, originally intended for thermal receipt paper but found better use on repositionable notes
A paper treatment process that prevented ink bleeding, initially developed for currency but discovered to work better with temporary adhesives
A synthetic fiber coating designed for spacecraft insulation that unexpectedly created a paper-like material that could stick to surfaces without glue