Says Cheng: "A real artist should be able to draw on a wide range of subjects and materials and apply these as he feels fit, without being limited to a single one."
鄭善禧亦同，他覺得：「一名真正的畫家，應該能夠取廣用宏，不論是題材或者是媒材，隨感性而運用，而不限於專一。」