<P> A Post-it Note (or sticky note) is a small piece of paper with a re-adherable strip of glue on its back, made for temporarily attaching notes to documents and other surfaces . A low - tack pressure - sensitive adhesive allows the notes to be easily attached, removed and even re-posted elsewhere without leaving residue . Originally small yellow squares, Post-it Notes and related products are available in various colors, shapes and sizes . </P> <P> Although 3M's patent expired in 1997, "Post-it" and the original notes' distinctive yellow color remain registered company trademarks, with terms such as "repositionable notes" used for similar offerings manufactured by competitors . While use of the trademark' Post-it' in a representative sense refers to any sticky note, no legal authority has ever held the trademark to be generic . </P> <P> In 1968, Dr. Spencer Silver, a scientist at 3M in the United States, was attempting to develop a super-strong adhesive . Instead he accidentally created a "low - tack," reusable, pressure - sensitive adhesive . For five years, Silver promoted his "solution without a problem" within 3M both informally and through seminars but failed to gain acceptance . In 1974 a colleague who had attended one of his seminars, Art Fry, came up with the idea of using the adhesive to anchor his bookmark in his hymn book . Fry then utilized 3M's officially sanctioned "permitted bootlegging" policy to develop the idea . The original notes' yellow color was chosen by accident, as the lab next - door to the Post-It team had only yellow scrap paper to use . </P> <P> 3M launched the product as "Press' n Peel" bookmark in stores in four cities in 1977, but results were disappointing . A year later 3M instead issued free samples directly to consumers in Boise, Idaho, with 94 percent of those who tried them indicating they would buy the product . The product was sold as "Post-Its" in 1979 when the rollout introduction began, and was sold across the United States from April 6, 1980 . The following year they were launched in Canada and Europe . </P>

Who is the inventor of post it notes