Royalp Tilsit is a Swiss cheese that was brought there by a Swiss cheesmaker who had learned to make Tilsir while in eastern Prussia after the Franco-Prussian war. It is a hard cheese made from cow's milk. The fat content is 45%. The affinage takes two to six months. Royalp Tilsit is a semi-hard, ivory-colored cheese with little holes and a browny-yellow rind.