The uniqueness of the Lalique crystal works lies in the meticulous work of retouching, engraving, and finishing, which represents two thirds of the time spent on production. Throughout the manufacturing process, a piece is checked at least ten times and may be rejected for a defect that is sometimes difficult to detect. The rejected pieces are broken and processed into ‘groisil’, which is reused in the melting furnace. Since 1921, the factory founded by René Lalique in Wingen-sur-Moder, in Alsace, has been perpetuating its traditional know-how. Today, it is still the only Lalique production site in the world.