The third principal typesetting machine is the Monotype, patented by Tolbert Lanston in 1887 and first produced commercially in 1897. The Monotype makes each character separately, assembling the characters as in hand composition, for which the Monotype characters can be used. Before electronic composition, monotype had an advantage in setting certain kinds of copy, e.g., mathematical and scientific material, where special symbols or other problems may be involved.