mezzotint vs oil

mezzotint

verb
  • To make such etchings 

noun
  • A form of intaglio etching in which a metal plate is roughened evenly and then smoothed to bring out an image. 

  • An etching or print made using this method. 

oil

verb
  • To grease with oil for cooking. 

  • To lubricate with oil. 

noun
  • petroleum 

  • petroleum-based liquid used as fuel or lubricant. 

  • Liquid fat. 

  • An oil painting. 

  • Oil paint. 

  • Containing oil, conveying oil; intended for or capable of containing oil. 

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