mark made by a seal or a stamp
Seal (emblem) The seal-making device is also referred to as the seal matrix or die; the imprint it creates as the seal impression (or, more rarely, the sealing).[1] If the impression is made purely as a relief resulting from the greater pressure on the paper where the high parts of the matrix touch, the seal is known as a dry seal; in other cases ink or another liquid or liquefied medium is used, in another color than the paper.
Post-it note 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.[1][2][3] 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.[4][5] Fry then utilized 3M's officially sanctioned "permitted bootlegging" policy to develop the idea.[5] 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.[6]