(also press copy), n. ~ A volume containing reproductions of correspondence, made directly from the originals using a transfer process.
Distinguish copies made using a transfer process and bound in a letterpress book from ink-on-paper works made using a letterpress1.
†(Yates 1989, p. 26–28) The first mechanical method of copying to gain widespread use in American business was press copying, first patented by James Watt in 1780 but not widely adopted in business until much later. As the technology came into common use, a screw-powered letter press was used in conjunction with a press book, a bound volume of blank, tissue paper pages. A letter freshly written in special copying ink was placed on a dampened page while the rest of the pages were protected by oilcloths. The book was then closed and the mechanical press screwed down tightly. The pressure and moisture caused an impression of the letter to be retained on the underside of the tissue sheet. This impression could then be read through the top of the thin paper. ¶ These letter presses were used by some individuals and businessmen in the first half of the nineteenth century, but they only came into general use in the second half of the century. ¶ A letter press reduced the labor cost, both by decreasing copying time and by allowing an office boy to do the copying once performed by a more expensive clerk. As the same time, it eliminated the danger of miscopying. Copies were now facsimiles of the letter sent, down to the signature.