Hmm.. is this sentence correct? Wiktionary and my Oxford give κεραμική as the noun for ceramic. κεραμικό looks to be the neuter adjective for ceramic. Although I'm still very new to this whole Greek thing, so I could be wrong.
Κεραμική is the art of creating things from ceramic materials. In the sentence above, κεραμικό is an adjective and "υλικό,σκεύος=material, vessel" is implied. So το κεραμικό acts like a "Nounified adjective" and means the "ceramic thing/vessel".