mezzotint vs rotogravure

mezzotint

noun
  • An etching or print made using this method. 

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

verb
  • To make such etchings 

rotogravure

noun
  • A print made by such a method. 

  • A printing process by which the paper is rolled through intaglio cylinders. 

  • A portion of a printed work produced by this method. 

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