The prominent splashes of purple, red or green on Jun-glazed wares were produced by potters who deliberately added copper to the glaze. Datable examples of Jun-glazed bowls with splashes were found in the tomb of Feng Daozhen (d. 1265) near Datong, Shanxi, excavated in 1958, and illustrated in Wenwu, 1962, no. 10, pp. 34-42, figs. 7-10.
Small Jun-glazed bowls with splashes both on the inside and out are highly sought after. Examples of 'bubble' bowls, mostly of below 9 cm. in diameter, include one in the Palace Museum, Beijing, illustrated in Porcelain of the Song Dynasty, The Complete Collection of Treasures of the Palace Museum, Hong Kong, 1996, p. 246, pl. 222 (8.3 cm. diam.); another in the collection of the Percival David Foundation, now housed at the British Museum, illustrated by S. Pierson, Song Ceramics: Objects of Admiration, London, 2003, p. 61, pl. 20 (PDF 45B) (8.6 cm. diam.); one in the Metropolitan Museum, illustrated by S. Valenstein, A Handbook of Chinese Ceramics, New York, 1975, p. 87, no. 80 (50.145.316) (8.6 cm. diam.).
Other examples are bowls illustrated by J. Ayers, The Baur Collection, Geneva, 1968, vol. 1, nos. A31 and A32 (both 8.5 cm. diam.); in the T.Y. Chao Private and Family Trust Collections, Part II, sold at Sotheby's Hong Kong, 19 May 1987, lot 209 (9.2 cm. diam.); and in the Edward T. Chow Collection, sold at Sotheby's London, 7 June 2000, lot 93 (9 cm. diam.).