Ideally the conservation / restoration of ancient copper objects should leave the patina intact for aesthetic reasons and for the purpose of better preservation. The original surface of the object (shape and size) should also be shown to better advantage. The conservation / restoration can be obtained by mechanic and / or chemical cleaning. In the case of the Benaki Museum’s censers, the conservation process included the cleaning and the fixing of the objects in an air vacuum. Last they were covered with an acrylic varnish.