bookfell vs vellum

bookfell

noun
  • A skin prepared for writing upon; a sheet of vellum or parchment; paper. 

  • A vellum or parchment manuscript. 

vellum

noun
  • A type of parchment paper made from the skin of a lamb, baby goat, or calf. 

  • A writing paper of very high quality. 

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