Riviera was introduced by The Homer Laughlin China Company in 1938. The Riviera line was pretty limited and was unmarked. It was much lighter in weight than Fiesta and Harlequin. Riviera came in yellow, light green, mauve blue and ivory. Red was temporarily stopped during the war. My yellow casserole does not have a stamp on the bottom. Riviera came from a line called Century. Century was an ivory line and was often decorated with a wide variety of decals. My Century casserole is marked with the year 1937.Also check out my Homer Laughlin Serenade.