holograph vs parchment

holograph

noun
  • A handwritten document that is solely the work of the person whose signature it bears, especially a letter, deed, or will; an original manuscript, a protograph. 

  • A hologram. 

verb
  • To record by means of holography. 

parchment

noun
  • A diploma (traditionally written on parchment). 

  • A document made on such material. 

  • The creamy to tanned color of parchment. 

  • Material, made from the polished skin of a calf, sheep, goat or other animal, used like paper for writing. 

  • The envelope of the coffee grains, inside the pulp. 

  • Stiff paper imitating that material. 

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