photomechanical vs photomechanics

photomechanical is not a noun while photomechanics is a noun.

Word	Noun	Adjective	Verb	Adverb
photomechanical	No	Yes	No	No
photomechanics	Yes	No	No	No

photomechanical (noun)	photomechanics (noun)
	the technique of using photomechanical methods to make photographs into plates for printing
	the process whereby printing surfaces (plates or cylinders) are produced by photographic methods

photomechanical (adjective)	photomechanics (adjective)
of or relating to or involving various methods of using photography to make plates for printing