Impresionist or Impressionist: How To spell?
The word Impresionist is misspelled against Impressionist, a noun meaning "One who adheres to the theory or method of impressionism, so called."
Impressionist has double "ss" is mispronounced as "s"Remember double 'SS' in between the strings impre & ionist which should not be misspelled with single 'S'
Wrong Spelling:  impre-s-ionist  Correct Spelling:  impre-ss-ionist 
Find more incorrect spellings of Impressionist to spell right way.