diaglyph vs woodcut

diaglyph

noun
  • Glyptic art consisting of a sunken or depressed engraving or carving on a stone or gem. 

woodcut

noun
  • An engraved block of wood, especially one used as a printing form. 

  • A method of printmaking from such a block. 

  • A print produced with this method. 

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