impressionistic vs impressionist

impressionistic is not a noun while impressionist is a noun.

Word	Noun	Adjective	Verb	Adverb
impressionistic	No	Yes	No	No
impressionist	Yes	Yes	No	No

As adjectives, impressionistic and impressionist are synonyms defined as:

impressionistic and impressionist: relating to or characteristic of Impressionism

impressionistic (noun)	impressionist (noun)
	an artist who follows the theories of Impressionism

impressionistic (adjective)	impressionist (adjective)
relating to or characteristic of Impressionism	relating to or characteristic of Impressionism
of or relating to or based on an impression rather than on facts or reasoning