If you are constantly asking what is my bathroom sink made of, then we have the answers for you. In the battle of porcelain vs. ceramic, porcelain wins, as it is much harder and less chip resistant. Its manufacturing process uses heavy heat treatment, mixing metal, glass, and clay for a stronger concoction. Our most durable sink is the #4 pick Mr Direct U1611-W Bathroom Sink, which uses vitreous china, a clay-based ceramic material widely known for its durability.