Bottle Vase, Qing dynasty (1644–1911), Qianlong reign mark and period (1736–95). Porcelain with blue glaze, 21.8 × 11.8 cm. Art Institute of Chicago, Bequest of Henry C. Schwab, 1941.668.1.

This porcelain vase features an even coating of a vibrant mottled turquoise glaze with speckles of deep red outlines. The extraordinary visual effect of this glaze, known as “robin’s egg” in English, is achieved by firing the turquoise glaze stippled with copper-red pigment at a lower temperature than that of the porcelain itself. Due to the low firing temperature, this glazing technique is referred to in Chinese as Lujun, or “furnace Jun.”

The development of this technique during the mid-Qing period stemmed from the numerous efforts of imperial potters to replicate the glaze found on Jun wares from previous dynasties. While the Lujun glaze echoes the striking color contrast and freeforming patterns of Jun ware, it also maintains its own distinctive visual appeal, testifying to the craftsmanship and innovative spirits of Qing potters. Bearing a Qianlong reign mark, this vase was likely crafted upon the order of the Qianlong Emperor.