However, as earthenware was heavy and fragile, a small bottle with a translucent, thick vinyl made body and a yellowish green-colored plastic made cap (a screw type lid) were introduced instead of a ceramic bottle in the late 1950s to the early 1960s.
しかし陶器は重量があり破損しやすいため、昭和30年代からそれらに代わって、半透明の厚いビニールの本体部分に黄緑色のプラスチックのスクリューキャップ（ネジ式の蓋）の付いた小瓶が導入された。