washable vs washproof

washable

adj
  • Capable of being washed without being damaged; especially by a specified method, for example machine-washable. 

noun
  • Something that can be washed without being damaged. 

washproof

adj
  • Capable of being washed without damage or loss. 

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