monoprint vs wood engraving

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. 

wood engraving

noun
  • A print taken from such an engraving. 

  • A variation of the woodcut method executed with a different tool (burin) and different wood (end grain), allowing for more detailed images. 

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