Hsieh had a Spanish direct-flame gas kiln specially imported so he could bring kiln temperatures to high levels quickly. Direct flaming raises the kiln temperature, making air oxidation more thorough during firing, in turn preventing impurities from sticking to the work due to incomplete oxidation.
為了讓瓦斯窯溫度能迅速達到高溫，謝嘉亨特地進口西班牙「直焰式」瓦斯窯；直焰，可以讓窯溫更高，窯燒時空氣氧化得更乾淨，避免胎體因氧化不完全而沾黏髒污。