carbon copy vs ectype

carbon copy

noun
  • Any duplicate. 

  • A duplicate copy of an email. 

  • A copy produced in an alternated stack of ordinary sheets of paper and carbon papers. The pressure applied on the top sheet (by a pen or typewriter) causes every carbon paper to release its carbon cover, thus reproducing the writing on the subjacent layers of paper. 

verb
  • To send a duplicate copy of an email to. 

  • To create a carbon copy of. 

ectype

noun
  • A copy, reproduction; especially as contrasted with the original, archetype, or prototype. 

  • An object in relievo or embossed. 

  • An idea or impression that corresponds to external reality. 

  • An impression (in wax, clay, &c.) of a seal or medal. 

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