engraving vs wallcovering

engraving

noun
  • A print produced from an engraving. 

  • The art of producing an image from an engraved printing form, typically made of copper. 

  • The art of drawing music notation at high quality, particularly on a computer. 

  • The practice of incising a design onto a hard, flat surface, by cutting grooves into it. 

wallcovering

noun
  • A covering for a wall, such as wallpaper 

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