Rubber Eraser Day takes place on April 15, 2018. It celebrates the invention of erasers, which allows you to kill your mistakes. On April 15, 1770, Joseph Priestley described a vegetable gum to remove pencil marks: "I have seen a substance excellently adapted to the purpose of wiping from paper the mark of black lead pencil." He dubbed the substance "rubber".
An eraser or rubber is an article of stationery that is used for removing pencil markings. Erasers have a rubbery consistency and are often pink or white. Some pencils have an eraser on one end. Typical erasers are made from synthetic rubber, but more expensive or specialized erasers are vinyl, plastic, or gum-like materials. Cheaper erasers can be made out of synthetic soy-based gum. (With material from: Wikipedia)