The term copper is derived from the word "cuprum" and refers to a semi-precious metal that is relatively light and easy to shape. It is the oldest metal known to humankind and is used in crafts. This fascinating metal reached an artistic peak in the 16th century with copperplate engraving. Picasso appreciated this graphic process for its sharp lines and thus helped it to a renaissance. Even in the field of sculpture, copper has conquered a permanent position.