Post-it Notes were invented through a collaboration between two 3M scientists: Spencer Silver and Arthur Fry. Spencer Silver originally invented the unique low-tack, reusable adhesive in 1968 while working to create a super-strong adhesive. However, the adhesive was initially considered a failure because it stuck lightly and could be removed without residue. Later, in 1974, Arthur Fry came up with the idea of using Silver's adhesive to create a bookmark that would stay in place without damaging pages. This idea evolved into Post-it Notes, which were officially launched in stores in 1980. Silver developed the adhesive, and Fry turned it into a practical office product, making both of them co-inventors of the Post-it Note.
In summary, Spencer Silver invented the adhesive, and Arthur Fry invented the practical use of that adhesive to create Post-it Notes.
