monoprint vs xylograph

monoprint

noun
  • A form of printing on paper from a glass sheet to which oil paint has been applied; monotype. 

verb
  • To print using this technique. 

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 monoprint and xylograph occurred in a corpus of books? (source: Google Ngram Viewer )