caulking vs sealskin

caulking

noun
  • A sealing material used to seal joints between heterogeneous materials in many kinds of construction and manufacture. 

sealskin

noun
  • Any fabric manufactured to resemble sealskin. 

  • A type of fabric made from the skin of seals. 

  • An item of clothing made from sealskin (whether real or imitation). 

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