Silicones or siloxanes, as they are also known, are something of a hybrid between synthetic rubbers and synthetic plastic polymers. They can take on different forms and be used to make malleable rubberlike items, hard plastic-like resins, and thick spreadable fluids.

Silicones have plastic-like properties: flexibility, malleability, clarity, temperature resistance, and water resistance. Like plastic, they can be shaped or formed and softened or hardened into practically anything. Since they’re easy to clean, nonstick, and nonstaining, they’re popular for cookware and kitchen utensils, too.