mirror image vs monoprint

mirror image

noun
  • An image that is reversed from left to right, as it would appear if seen in a mirror; a reflection. 

monoprint

noun
  • A form of printing on paper from a glass sheet to which oil paint has been applied; monotype. 

verb
  • To print using this technique. 

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