The painting, found in a bedroom in the 1960s, was originally hung in the main living room used by the Parker family, owners of Saltram.
The wallpaper is being restored by two conservators, Mark Sandiford and Phillippa Mapes. Before removing the paper from the bedroom wall at Saltram, they glued tissue paper on to it to protect the surface. They then removed portions of the tissue to work on the damaged sections.
The silk, which is extremely fine, forms the surface layer, backed by several different lining papers. To remove the papers, the conservators placed the painting upside down and moistened the back. It was then relined with a strong but extremely lightweight Japanese hand- made paper. 'We have to work fast because the painting will wrinkle up like a poppadom if it dries out without a backing paper on it,' Miss Mapes said.
The painting shows workers picking tea in plantations, sieving it and packing it in large baskets. The tea is then distributed by boat and finally ends up in tea shops where mandarins in fine robes delicately sip it.
Some of the scenes have been damaged over the years. These will be repaired by placing fine paper over the affected areas, painting in a matching colour and continuing any lines across the patch so the eye is not distracted.
The wallpaper will be returned to Saltram for the re- opening of the house at Easter. It will form part of a collection of late 18th-century art, including English pictures, furniture, and a wide range of Chinoiserie. John Parker, later Lord Boringdon, who remodelled the house in 1768 to 1772, had strong maritime connections, so acquired a very complete collection of articles from the Chinese trade, which boomed in the late 18th century before large scale tea plantations were developed in India.
Staff at a National Trust stately home near Wrexham, Clwyd, have found a strip of green wallpaper decorated with pineapples that could be up to 280 years old and possibly one of the best examples of 18th-century wallpaper ever discovered in the UK.
'It's certainly a very old piece,' Robert Dillon, property manager at the Erddig stately home, said. 'It has an excise stamp on it, which means we can almost certainly date it to between 1712 and 1714.'