Abstract: A seamless laboratory countertop (10) including an inner core (38) of relatively lightweight rigid material having top and bottom surfaces and at least one side surface extending between the top (42) and the bottom (44) surfaces. A reinforcement layer (40) of fiber-reinforced thermoset resin is secured to and covers the top and the bottom surfaces of the inner core (38), and a layer of thermoset resin is secured to and covers the side surface of the inner core. The thermoset resin on the side surface is the same as the thermoset resin of the reinforcement layer. The countertop also includes an outer layer (12) of non-reinforced thermoset resin secured to and covering the reinforcement layer over the top surface of the inner core to provide a smooth work surface.