A fine copper-red glazed winecup, Mark and period of Yongzheng. Photo: Sotheby's

delicately potted with curved sides rising to a straight mouth, the exterior applied overall with a slightly mottled copper-red glaze of vivid crushed-raspberry tone, draining to white from the rim and pooling to a darker colour around the foot, the interior and base reserved in white, the base inscribed in underglaze blue with a six-character reign mark; 7.3 cm., 2 7/8  in. Estimation 3,000,000 - 4,000,000 HKD. Unsold

Provenance: Collection of Dr. Ip Yee.
Sotheby's Hong Kong, 19th November 1984, lot 219.
Sotheby's Hong Kong, 29th/30th April 1997, lot 589. 

At the end of the Kangxi period the use of copper-red was revived in a variety of ways to achieve different glaze effects and was perfected during the Yongzheng reign. The craftsmen’s thorough understanding of the pigment allowed them to manipulate the changes that occurred due to firing, such as its tendency to turn pale rose-pink or green, to great aesthetic effect.