caulking vs signet

caulking

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

signet

noun
  • an object (especially a ring) formerly used to impress a picture into the sealing wax of a document as a proof of its origin 

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