sackcloth vs sailcloth

sackcloth

noun
  • A coarse hessian style of cloth used to make sacks. 

  • Garments worn as an act of penance. 

adj
  • Made of sackcloth. 

sailcloth

noun
  • A strong, durable fabric suitable for making sails for ships or boats. 

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