stencil vs touchstone

stencil

noun
  • A pattern produced using such a utensil. 

  • A two-ply master sheet for use with a mimeograph. 

  • A thin sheet, either perforated or using some other technique, with which a pattern may be produced upon a surface; a utensil that contains a perforated sheet. 

verb
  • To print with a stencil. 

touchstone

noun
  • A stone used to check the quality of gold alloys by rubbing them to leave a visible trace. 

  • A standard of comparison or evaluation. 

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