Correction fluid is a liquid product designed to cover mistakes made while typing, hand writing, or photocopying markings on paper. Typically, it is applied to paper using a brush. When it dries, it forms a solid film that effectively covers the error and allows the correct mark to be written over it. Correction fluids are composed of pigments, polymeric binders, and solvents that are mixed together in large batch tanks. First developed during the late 1950s, correction fluid formulations have steadily improved over the years.