cartouche vs metal plate

cartouche

noun
  • A paper cartridge. 

  • A wooden case filled with balls, to be shot from a cannon. 

  • A gunner's bag for ammunition. 

  • A military pass for a soldier on furlough. 

  • An ornamental figure, often on an oval shield. 

  • An oval figure containing the characters of an important personal name, such as that of royal or divine people. 

metal plate

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