letters vs typeface

letters

noun
  • Literature (school subject). 

  • The liberal arts, humanities, learning (broad accumulated cultural knowledge). 

typeface

noun
  • The surface of type which inked, or the impression it makes. 

  • The particular design of some type, font, or a font family. 

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