Engineered composites expert witnesses may opine on vinyl chloride polymers, electroactive polymers, functional polymers, and more. Here, the International Cast Polymer Alliance describes cultured marble, cultured granite and cultured onyx:
Cultured Marble, Cultured Granite and Cultured Onyx, as their names imply, have the look of genuine marble, granite or onyx. Cultured marble, granite and onyx products are usually manufactured with a high-gloss coating, called a “gel coat”, applied during the manufacturing process, which becomes an integral part of the cultured marble, granite or onyx product. Colorants may be added to the polymer/filler matrix in a manner which provides a “veining” which mimics the appearance of natural products. The polymer casting process yields a rock hard, durable product which takes on the look and feel of the natural product.