hairpiece vs weft

hairpiece

noun
  • A false substitute for a person's hair; a toupee or wig. 

weft

noun
  • A hair extension that is glued directly to a person′s natural hair. 

  • The horizontal threads that are interlaced through the warp in a woven fabric. 

  • The yarn used for the weft; the fill. 

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