A FINE 'SKY BLUE' 'JUN' BOWL SONG / JIN DYNASTY

the steep rounded sides rising to a delicately incurved rim, covered overall in an evenly applied and fine 'sky blue' glaze of milky lavender blue suffused with a pale crackle and draining to a mushroom tone at the rim, the glaze pooling unevenly above the unglazed neatly pared ring foot, Japanese wood box

The bowl is in good condition. It has a shallow firing chip under the footrim and slight kiln adhesion to the foot.
In response to your inquiry, we are pleased to provide you with a general report of the condition of the property described above. Since we are not professional conservators or restorers, we urge you to consult with a restorer or conservator of your choice who will be better able to provide a detailed, professional report. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Sotheby's is merely a subjective qualified opinion.
NOTWITHSTANDING THIS REPORT OR ANY DISCUSSIONS CONCERNING CONDITION OF A LOT, ALL LOTS ARE OFFERED AND SOLD "AS IS" IN ACCORDANCE WITH THE CONDITIONS OF SALE PRINTED IN THE CATALOGUE.

'Jun' ware has been much admired over the centuries by both Chinese and Western connoisseurs for the beauty of its glaze, its depth and intensity; this particular shade of sky blue being understood as the ideal color for the monochromatic version of the ware. Over the years there has been much speculation surrounding the methodology and technology of the famous glaze. Understanding how the glaze was created proved elusive until the late 1980s when it was discovered that the blue tone is not created by pigments at all but is actually an optical effect. During firing the 'Jun' glaze separates into light-scattering droplets of glass and when light passes through this ‘glass emulsion’, the blue spectrum of light is reflected, giving the ware its bluish hue. The thickness of the glaze is a critical factor in creating the optical blues. It has been thought that this was a consequence of multiple layers, but analyses of sectioned shards done at the kiln sites indicate that only a single layer is applied and that the depth of glaze is attributable to the thick body, as water from the glaze is absorbed by the porous biscuit resulting in a more substantial covering.