Bette Nesmith Graham was not a very good typist. Still, the high school dropout worked her way through the secretarial pool to become the executive secretary for the chairman of the board of the Texas Bank and Trust. It was the 1950s, and the electric typewriter had just been introduced. Secretaries often found themselves retyping entire pages because of one tiny mistake, as the new model's carbon ribbon made it difficult to correct errors.
One day, Graham watched workers painting a holiday display on a bank window. She noticed that when they made mistakes, they simply added another layer of paint to cover them up, and she thought she could apply that idea to her typing blunders. Using her blender, Graham mixed up a water-based tempera paint with dye that matched her company's stationary. She took it to work and, using a fine watercolor brush, she was able to quickly correct her errors. Soon, the other secretaries were clamoring for the product, which Graham continued to produce in her kitchen.
Graham was fired from her job for spending so much time distributing what she called "Mistake Out," but in her unemployment she was able to tweak her mixture, rename the product Liquid Paper and receive a patent in 1958. The product became indispensable in the days before widespread use of computers. Nesmith sold Liquid Paper to Gillette for $47.5 million in 1979. Sidenote: Her son Mike was a member of the '60s group the Monkees.