mezzotint vs wood engraving

mezzotint

noun
  • A form of intaglio etching in which a metal plate is roughened evenly and then smoothed to bring out an image. 

  • An etching or print made using this method. 

verb
  • To make such etchings 

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 mezzotint and wood engraving occurred in a corpus of books? (source: Google Ngram Viewer )