unwashable vs washable

unwashable

noun
  • Something that cannot be washed in the normal way without being damaged. 

adj
  • Not washable; that cannot be washed. 

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. 

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