A sink includes a bottom surface forming an opening for drainage therein, a first sidewall, a second sidewall, a third sidewall, and a fourth sidewall, each of which is extended from the bottom surface, and a ledge fixedly attached to top ends of the first, second, third, and fourth sidewalls. The bottom surface and the first, second, third, and fourth sidewalls have a same thickness, and a thickness of the ledge is different from the thickness of the bottom surface.