This canteen-shaped flask (janggun) presents the characteristic form of the type: a horizontally elongated, flattened body with a slightly flared mouth opening set into the upper surface. Dense white slip is applied as an overall ground across the entire surface; the field is then organized by incised dividing lines, and across both faces of the body swiftly rendered, rhythmically vital grass-leaf motifs (choyeop) are painted in underglaze iron brown, while plantain leaf (pacho) designs are placed at four points around the mouth rim. The glaze is transparent and even in luster. Vessels of this canteen form enjoyed widespread use as wine flasks for outdoor and field settings, and appear in diverse forms throughout the Buncheong tradition of the fifteenth century. This outstanding example is distinguished by the seamless accord between its densely applied white slip ground and the boldly painted iron-brown grass-leaf motifs — rendered with a swift, soaring energy as though about to take flight. The piece was produced at the Hakbong-ri kiln in Gongju during the latter half of the fifteenth century.