"He laid out on the paper ranges of lofty mountains as is typical in a Song painting. But he also left blank areas so that the painting did not have a high density of subjects," says Cheung.

"He worked out shimmering river waves as neatly as a fishing net. It shows how much time and energy he invested in the painting."

For decades, Zhang was one of the world's most-popular ink artists of the 20th century.

But Cheung says it is only when the art market experiences ups or downs that quality traditional Chinese paintings like Zhang's works register a steady and outstanding performance in the markets.

"The industrious painter had a productive career, even though few high-quality works from different phases of his career are available for sale now," he says.

Meanwhile, the Chinese art market has continued to shrink since spring even though Zhang's works are doing well.

His huge splashed-ink-and-color work, Peach Blossom Spring, sold for HK$270 million ($34 million) in Hong Kong in April, setting an auction record for the artist.

Separately, at a Christie's sale of Chinese ink paintings on Sept 13 in New York, Zhang's works made seven of the top 20 sales.

Other works that have appeared in Sotheby's auctions are Zhang's Buddhist Mural Painting after Tang Artists, a figure painting inspired by his two-year study of Dunhuang cave art in the early 1940s, and the splashed-ink-and-color Sage by the Pine.

In a related development, several works by Fu Baoshi (1904-65), another master ink painter, including Warriors on the Night March, are slated to go under the hammer soon.

Fu's colored-ink painting God of Cloud and Great Lord of Fate grossed 230 million yuan ($34 million) at a Beijing auction in June.