Tipp-Ex errors" (German: "Tippfehler"). He subsequently founded a company of the same name. Shortly after that a "Tipp-Ex Sales & Distribution" company (Tipp-Ex Vertrieb GmbH & Co. KG) was founded in Frankfurt by Otto Carls. This company still exists under the name of Tipp-Ex GmbH & Co. KG close to Frankfurt. "Tipp-Ex" became a registered trademark with the German patent office in 1987. Earlier, in 1951, Bette Nesmith Graham invented the first correction fluid in her kitchen and began marketing the product in 1956 as "Mistake Out", later called Liquid Paper. Tipp-Ex GmbH only started to produce white correction fluid in
Nesmith Ankeny Nesmith Ankeny Nesmith Cornett Ankeny (1927, Walla Walla, Washington – 4 August 1993, Seattle) was an American mathematician specialising in number theory. After Army service, he studied at Stanford University and obtained his Ph.D. at Princeton University in 1950 under the supervision of Emil Artin. He was a Fellow at Princeton and the Institute for Advanced Study, then assistant professor at Johns Hopkins University from 1952 to 1955, when he joined MIT. He was a Guggenheim fellow in 1958; he became a full professor in 1964 and retired in 1992. His research was mainly in analytic number theory, on consequences