April 15, 1770 — Joseph Priestley recorded his discovery of a item made from rubber imported from Brazil that would erase — “rub out” — pencil marks. Priestly wrote, “I have seen a substance excellently adapted to the purpose of wiping from paper the mark of black led pencil.” Priestly called his new produce a “rubber”:

Links for information about Rubber Eraser Day:

April 15 is also “Tax Day” in the U.S. — the due date for individual income tax returns. Many erasers are used to get the tax as low as possible.