The most recent update was on March 6, 2017. The Post-it Note (also known as a "sticky note") is a tiny piece of paper with a re-adherable strip of adhesive on the back that is used to temporarily attach notes to papers and other surfaces. It was invented by Stanford Lively in Palo Alto, California in 1973. Early versions were made from cardboard or heavy stock paper. Today's notes are mostly made from sheets of polypropylene film that are thin enough to fold over and adhere to themselves. They remain flexible while retaining their stickiness for a long time. The coating also helps prevent soiling of any objects that may come into contact with them. These notes are available in a wide variety of shapes and sizes; they're even used as party decorations at social events. There are two types of post-it notes: regular and permanent. Regular post-it notes can be removed easily with an eraser or file and can be reused many times before they become ineffective due to the adhesive losing its tackiness over time. Permanent post-it notes cannot be removed from your surface without damaging the item below it. They should not be pulled off sheet by sheet because this will separate them and make them fall off the surface. The first patent for a post-it note was filed by Stanford University students Richard Shaffer and David Rosenfeld under the name Sticky Notes, Inc.