trial impression vs test copy

trial impression and test copy both are nouns.

Word	Noun	Adjective	Verb	Adverb
trial impression	Yes	No	No	No
test copy	Yes	No	No	No

As nouns, trial impression and test copy are synonyms defined as:

trial impression and test copy: (printing) an impression made to check for errors

Other synonyms of trial impression include proof.

trial impression (noun)	test copy (noun)
(printing) an impression made to check for errors	(printing) an impression made to check for errors