tempera vs varnish

tempera

noun
  • A painting done in this medium. 

  • A medium used to bind pigments in painting, as well as the associated artistic techniques. 

varnish

noun
  • A type of paint with a solvent that evaporates to leave a hard, transparent, glossy film. 

  • Anything resembling such a paint; glossy appearance. 

  • A deceptively showy appearance. 

verb
  • To make something superficially or deceptively attractive 

  • To gloss over a defect. 

  • To cover up with varnish. 

  • To apply varnish. 

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