printing vs impression

printing and impression both are nouns.

Word	Noun	Adjective	Verb	Adverb
printing	Yes	No	No	No
impression	Yes	No	No	No

As nouns, printing and impression are synonyms defined as:

printing (noun)	impression (noun)
the business of producing printed material for sale or distribution	an impressionistic portrayal of a person
reproduction by applying ink to paper as for publication	the act of pressing one thing on or into the surface of another
text handwritten in the style of printed matter	(dentistry) an imprint of the teeth and gums in wax or plaster
all the copies of a work printed at one time	an outward appearance
	a vague idea in which some confidence is placed
	a clear and telling mental image
	a symbol that is the result of printing or engraving
	all the copies of a work printed at one time
	a concavity in a surface produced by pressing