gravure vs photogravure

gravure

noun
  • A type of intaglio printing process, in which an image is engraved onto a rotating copper cylinder. 

  • A style of Japanese softcore; glamour photography. 

photogravure

noun
  • An intaglio process for printing photographic reproductions in newspapers and books. 

  • A print so made. 

verb
  • To print by this process. 

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