Gauge is a physical measurement of the thickness of copper. Copper is a soft material and the thickness that you choose in your sink or tub should be a major part of your purchasing decision. The lower the gauge number the thicker the metal is. For example, 14 gauge copper is thicker than 18 gauge. The gauge you choose can be substantial as to how the product will wear over time. Here at Diamond Spas the only gauge of copper we use in our products is 14 to 16 gauges, and the same goes for stainless steel. We believe anything higher such as an 18 to 20 gauge is too thin to use in water vessel containment. The higher gauge metals tend to leak overtime and also give off the “tinny” sound when something is placed in a sink such as a dish or even water rushing from a faucet. Denting is also something to consider. The higher gauge metals are much softer making it easier to dent and warp. Being in this business for over 13 years, we have heard from many unhappy people who have purchased cheap copper sinks online only to find out later that they are denting and leaking. When shopping for a metal sink, always ask what gauge of metal is in the product. You will pay more for lower gauge copper, but the higher cost pays for itself in that you are purchasing a lifetime product.