photostat vs xylograph

photostat

noun
  • A photocopy made using a photocopier. 

  • Positive (black on white) or negative (white on black) reproduction of printed matter or artwork made on a photostat machine, which uses photographic paper instead of a transparent negative, and uses a prism to render the paper negative readable instead of reversed. 

verb
  • To make such a photocopy of. 

xylograph

noun
  • A print taken from such an engraving. 

  • An engraving in wood or woodcut, especially one used in printing predating the Western tradition (14th c.). 

verb
  • To make a print from an engraving in wood. 

How often have the words photostat and xylograph occurred in a corpus of books? (source: Google Ngram Viewer )