Txawm hais tias nws yog cov duab puab loj hauv nroog, cov duab puab toj roob hauv pes, lossis cov duab puab sab hauv tsev ntawm lub txee, cov khoom siv tooj liab yog cov khoom siv duab puab nyiam los ntawm cov sculptors.Copper carvings muaj qhov zoo ntawm hardness, corrosion kuj, thiab ntev lifespan, thiab yooj yim rau khaws cia.Yog li ntawd, lawv muaj tus yam ntxwv ntawm lub sijhawm tsis muaj sijhawm thiab yuav tsis dhau los nrog cov qauv ntawm lub sijhawm.