etch vs stencil

etch

verb
  • To cut into a surface with an acid or other corrosive substance in order to make a pattern. Best known as a technique for creating printing plates, but also used for decoration on metal, and, in modern industry, to make circuit boards. 

  • To engrave a surface. 

  • To make a lasting impression. 

  • To sketch; to delineate. 

stencil

verb
  • To print with a stencil. 

noun
  • 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. 

  • A pattern produced using such a utensil. 

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