Bette Nesmith Graham was a typist who became an inventor thanks to her discovery of the famous liquid paper (corrector). To make extra money, Bette was painting holiday windows at the bank. She realized that an artist never corrects their mistakes by erasing, but instead just paints over them, and that’s how she got the idea of creating a correction fluid. Over the years, she perfected the chemical formula of the fluid with help from her son’s chemistry teacher, and in 1956 she began marketing her typewriter correction fluid as “Mistake Out.”