test copy vs printing

test copy and printing both are nouns.

Word	Noun	Adjective	Verb	Adverb
test copy	Yes	No	No	No
printing	Yes	No	No	No

As nouns, printing is a hypernym of test copy; that is, printing is a word with a broader meaning than test copy:

Other hypernyms of test copy include impression.

test copy (noun)	printing (noun)
(printing) an impression made to check for errors	the business of producing printed material for sale or distribution
	reproduction by applying ink to paper as for publication
	text handwritten in the style of printed matter
	all the copies of a work printed at one time