A pastry bag is an often cone- or triangular-shaped bag made from cloth, paper, plastic, or the intestinal lining of a lamb, that is squeezed by hand to pipe semi-solid foods by pressing them through a narrow opening at one end often fitted with a shaped nozzle, for many purposes including in particular cake decoration and icing. It is filled through a wider opening at the opposite end, rolled or twisted closed, and then squeezed to extrude its contents. Many differently shaped nozzles are used to produce cross-sections such as star, leaf, and flower-petal shapes; a simple circular nozzle makes round shapes and is also used for filling pastries such as profiteroles.