Vessels that held water for rinsing ink out of a brush were among a scholar’s essential tools for painting and calligraphy. This flower-shaped brush washer is one of the finest works in the BMA’s Asian art collection. The porcelain body is refined and dense. The glaze, a palest blue, is luminous. The intensity of the cobalt design reveals that the pigment was carefully prepared, although over-concentration produced the distinctive “heaped and piled” inky spots. Pairs of thin lines define the vessel’s shaped rim and encircle the central motif, which is painted in strong and energetic outlines filled with carefully applied washes, and is restated around the exterior in ten shaped frames. The design’s balance, execution and placement on the undecorated surface of the vessel are features of imperial-quality porcelain of this time. The brush washer’s shape is based on Chinese Tang dynasty (618–907) foliate mirrors. Trace amounts of iron in the local clay, fired in the reduction atmosphere of the early Jingdezhen kilns, resulted in the pale bluish tone. Other elements derive from foreign influences. The Islamic world’s preference for blue-and-white ceramics prompted the use of cobalt pigment to decorate Chinese white porcelain during the Yuan dynasty (1271–1368). The cobalt ore was imported from Persia, while flower, leaf and vine decoration was brought to China with Buddhist imagery of the 3rd–5th century.