This flat bottle (pyeonbyeong) exemplifies the classic form of the type: the body is shaped by pressing both faces to an even, flattened profile; a slightly flared mouth rim rises above; and a thin, low foot ring anchors the base. The entire surface is coated with white slip applied rapidly and broadly by the guiyal brush technique, and it is this quality — the swift, kinetic energy of the brushstrokes and the spontaneous traces of the brush hairs — that constitutes the vessel's sole and sufficient decoration, playing against the pale grayish-blue of the clay body beneath with a natural and effortless vitality. The glaze is transparent and thinly applied, with an even, refined luster. Traces of sand kiln supports remain on the foot ring. Produced at a kiln in the Honam region during the first half of the sixteenth century, this bottle relies on nothing beyond the guiyal slip technique itself — yet the expressive immediacy of the brushwork achieves a decorative effect of quiet but unmistakable power, and the piece stands as a consummate example of the guiyal Buncheong tradition at its most assured.