The shape of the tube varried from an octangular prism or circular cylinder with long pieces of wood glued on which a spiraling groove was cut inside the bamboo processed evenly or one made of rolled Japanese paper coated inside and outside with urushi Japanese lacquer.
筒は木製で長尺の木に半円の溝を彫ったものを張り合わせた八角柱や円柱の筒や、竹の内側を均等に加工したものや和紙を丸めたものがあり、それぞれの筒の内や外に漆を塗ったものがある。