Thinking about renovating your kitchen? If so, then our Sink Spotlight series will help you. Up today: undermount sinks. 1. Distinctive Features: The edge lip of the sink is mounted below a solid surface countertop, so the sink effectively hangs underneath the counter, as opposed to sitting on top of it; creates a continuous flow from countertop into sink. 2. Countertop Compatibility: Best suited for solid surface materials like granite countertops, soapstone, marble, or concrete.