Polyboards are polystyrene boards that usually measure 4 feet wide by 8 feet high and are normally 2 inches thick. One of the other defining characteristics is that they are often white on one side and black on the other. Either of their side can be used for different purposes. White to bounce back a source of light to the model or a product, black to sharpening the shadows on the model or the product.
Alternative
WHITE CLOTH, WHITE FOAM BOARD.