Blue-and-white Covered Jar with Underglaze-red Patterns in Open Work

The jar has a straight mouth, a short neck, a swollen stomach, and an unglazed foot ring. The knob on the cover is in the form of a squatting lion, below which is painted a blue-and-white circular design that includes lotus, tendrils, and meandering patterns. The mouth rim and the lower part of the stomach have interlocking flowers and tendrils. The shoulder is covered with a design of cloud-shaped heads of ruyiscepters, in which white lotus grow out of ripples. Between the ruyi scepters are interlocking peony blossoms. The stomach has four rhombic framed panels displaying various landscapes of the four seasons. Carved in low relief, the rocks and flowers use underglaze red. Above the foot ring are more tendrils and stylized lotus. With a swollen shape and distinct design, the jar combines diverse techniques including painting, engraving, sculpting, and applique. The blue and underglaze red complement each other.
Blue-and-white glaze with patterns in underglaze red was an innovation of the Yuan dynasty. The blue is attributed to cobalt oxide (CoO), which manifests a stable color. The underglaze red is copper hemioxide (Cu2O) that is volatile. Thus, the combination of two materials with contradictory properties requires a perfect oxygen atmosphere. Wares with underglaze colors reveal sophisticated techniques of the Yuan dynasty.
The blue-and-white jar with patterns in underglaze red is one of two similar containers unearthed from a Yuan dynasty kiln in Baoding, Hebei Province in 1965.