Gelcoat, sometimes written as "Gel Coat," is a crucial material used to achieve a high-quality finish on the visible surface of fiber-reinforced composites. The most common gelcoats are thermosetting polymers formulated using epoxy or unsaturated polyester resin chemistry. These modified resins are applied in a liquid state to molds, where they cure to form crosslinked polymers. Subsequently, they are backed with thermoset polymer matrix composites, typically mixtures of polyester resin and fiberglass. However, for applications requiring higher specific strength, epoxy resin paired with carbon fiber is the preferred choice.