Ruban Yu began his study on the firing of glazes after work and has done research on glazes from traditional Chinese celadon, Jun glaze, copper red, oil Tenmoku, blue-and-white porce- lain⋯ all the way to Japan’s Oribe and Shino glaze.
He successively purchased two electric gas kilns, one type of Hengyan type gas kiln, and one wood-fired kiln. Mainly focusing on glaze creation. Layered glaze color, and then use the vir- tual and real space on the glaze color to add color, few people in the world create this way.
余悅余快剛開始以礦物釉為主，慢慢的轉向天然的草木灰釉，並開始到山裏挖掘土石，自己 配土及使用各種天然可以取得的原料，如:咖啡粉、蚵貝灰、炭化稻殼、海帶粉、天然海鳥屎⋯
陸續採購二座電瓦斯窯、一型橫炎式瓦斯窯、一座柴窯，主要以釉藥創作為主，其中水磨多 次燒出多層次釉色，再利用釉色上的虛實空間進行加彩，世界上比較少有人如此創作。