In 1968 an employee of the development laboratory of the company 3M tried to improve the scotch quality. As a result of his experiment the thick adhesive was obtained which did not absorb into the surfaces glued and was completely useless for scotch production. Four years later his colleague who sang in a choir at loose hours was irritated in that the bookmarks in the Book of Psalms constantly fell out. Thus he remembered of the adhesive which could stick the paper bookmarks without damaging book pages. First post-it notes were put on the market in 1980.