epigraph vs gravure

epigraph

noun
  • An inscription, especially on a building. 

  • A literary quotation placed at the beginning of a book or other text. 

  • The set of all points lying on or above the function's graph. 

verb
  • To provide (a literary work) with an epigraph. 

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. 

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