For this reason Cheng made a special trip to the Linkou Plateau to collect red clay. But he found this material impossible to get into the right shape, so he had to add a certain proportion of general-purpose potter's clay.
為了表現正確的色澤，鄭永國特別到林口台地挖紅土來製作，但是他發現根本無法成形，只好加入陶土，作某種比例的混合。