The history of the development and use of library handwriting in the cataloging practice of different countries of the world (USA, Germany, Russian Empire, USSR) is considered. Special attention is given to the study of the stage of creation of library handwriting in the USA at the end of the 19th century in the context of the activities of the American Library Association and the first library schools. The main tasks, characteristics and features of library handwriting as a special direct handwritten font are disclosed. Requirements for library handwriting are analyzed, such as legibility, clarity, simplicity, speed, uniformity, compactness, thriftiness, refinedness, lack of pressure, etc. The definition of the term "library handwriting" is proposed. The practical significance of library handwriting for the development of library catalogues in the 19th and 20th centuries was determined. The contribution of individual librarians and persons of other fields (T. Edison, M. Dewey, E. Ackerknecht, Yu. Hryhorev, M. Dobrov, M. Burns) to the creation and development of library writing was described.