Book smarts, beautifully applied. This Princeton® Collection bathtub is made of Americast®, our revolutionary alternative to cast iron that's more durable, lighter and costs less to install. Features include a traditional glossy porcelain finish, beveled headrest, lumbar support and a slip-resistant surface. Alcove installation. Learn more about Americast. Americast® is our proprietary, revolutionary alternative to cast iron that's more durable, lighter and costs less to install. Thanks to inherent manufacturing advantages, Americast bathtubs can be made deeper, flatter and roomier than their cast iron counterparts.