blotter acid vs cardboard

blotter acid

noun
  • Blotter paper impregnated with the drug LSD, to be taken orally. 

cardboard

noun
  • A wood-based material resembling heavy paper, used in the manufacture of boxes, cartons and signs. 

adj
  • Made of or resembling cardboard; (figurative) flat or flavorless. 

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