Letterpress. Among scholarly editors, a term used to describe an eighteenth- and early-nineteenth-century method for creating facsimile copies of outgoing corresponcence, in which a thin, nearly transparent sheet of paper was moistened and pressed against the inscribed surface of handwritten material. Ideally, enough ink was transferred from the original to the back of the blank sheet so that the handwritten words showed through, giving a legible and complete copy. In the mid-nineteenth century, chemically treated paper replaced moistening agents. Also used to describe printing technologies in which printed pages are produced by pressing sheets of paper against inked type.
(Kline 1998, 272)