papyral vs papyrine

papyral

adj
  • Of or pertaining to papyrus or paper. 

papyrine

adj
  • Of or pertaining to papyrus or paper. 

noun
  • A kind of vegetable parchment, made by soaking unsized paper in dilute sulphuric acid. 

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