What is "basse-taille"

Basse-taille (bahss-tah-ee) is an enamelling technique in which the artist creates a low-relief pattern in metal, usually silver or gold, by engraving or chasing. The entire pattern is created in such a way that its highest point is lower than the surrounding metal. A translucent enamel is then applied to the metal, allowing light to reflect from the relief and creating an artistic effect. It was used in the late Middle Ages, and then again in the 17th century.