To prepare the bottles for painting, diamond sand and small steel balls were placed inside and shaken for several hours to scratch the surface of the glass, a process which allowed the paint to adhere.
在做內繪之前，先要將小鋼珠和礦石砂倒進玻璃瓶中攪拌數小時，使瓶子內壁變得粗糙，以便著色。