A copper-red-glazed vase, meiping, Yongzheng. Photo Bonhams.

Elegantly potted with broad shoulders tapering down to a slightly flared base, with a short flared neck, covered in an attractive even deep red glaze. 21.2cm high. Estimate HK$ 380,000 - 450,000 (€37,000 - 43,000). Unsold

The rich red glazed derived from copper oxide was first used at Jingdezhen in the fourteenth century as an underglaze pigment, usually mixed with iron oxide to give the rich maroon coloured glaze. By the Qing Dynasty, however, the colourant was composed of copper-lime mix without the presence of iron, hence it was considered one of the most difficult underglazed pigment to fire, due to the volatility of copper causing over-firing and wastage. As firing of the underglazed copper red pigments require temperatures in excess of one thousand two hundred and fifty degrees Celsius, but can only be consistently controlled by using wood-burning kilns, the ceramic wares cost three to four times more than other porcelain fired during this period.

Copper red monochromes are generally fired in a reducing atmosphere, where the richness of the colour is greatly enhanced by a short period of re-oxidation during the end of the firing cycle. This process is tiresome and often misfired, as a slight miscalculation in time and technique will result in the copper glaze turning green.

Compare with a copper-red meiping with a Yongzheng six-character mark and of the period currently preserved in the Palace Museum, Beijing, illustrated in The Complete Collection of Treasures of the Palace Museum, Monochrome Porcelain, Hong Kong, 1999, p.27, pl.24. For more examples of copper-red meipings , with Yongzheng mark, offered at auction, see a slightly larger vase sold in Christie's New York, 19 September 2007, lot 344; and another identical in size to the present lot, sold in Christie's Hong Kong, 1 June 2011, lot 3616.

Bonhams. FINE CHINESE CERAMICS AND WORKS OF ART. Hong Kong, Admiralty, 26 May 2014