rotogravure vs woodblock

rotogravure

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

  • A print made by such a method. 

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

woodblock

noun
  • A wooden block used as a printing form. 

  • The emergency issue of the Cape triangles, printed in 1861. 

  • A woodcut. 

  • A percussion instrument consisting of a hollow block of wood struck with a drumstick. 

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