Traditional Burgundian glazed tiles made of clay spread in wooden templates are rectangular and flat. The technique of colored glaze - by applying a slip based on clay, water, and metallic oxides (copper for green, iron for yellow, manganese for brown-red, etc.) that reveal their color after cooking - was already known to the Romans who used it for culinary pottery. It was extended to architectural terracottas (floor and roof tiles) from the 13th century. The clayey soil of Burgundy has favored the development of local tile factories since the Middle Ages, ensuring the supply of many building sites.