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.