Only one piece of street calligraphy by the late Tsang Tsou-choi will be preserved in a protective case by the end of this month. But other remaining pieces of work by the 'King of Kowloon' will stay exposed until the government's heritage-conservation experts can think of a way to protect them. The Leisure and Cultural Services Department's chief conservation curator, Chan Shing-wai, said a pillar at the Tsim Sha Tsui Star Ferry pier would be housed in a transparent case of polycarbonate 12mm thick. Mr Chan said the case could withstand wind and rain and resist the sun's ultraviolet rays. Work was expected to be completed on June 24, he said, adding that a small plaque introducing Tsang, who died at 86 in 2007, and his work would be placed at the site. A stainless-steel framework will be installed to support the nearly 2.5-metre-tall protective case, which will be 13cm from the pillar's surface. The project will cost HK$73,000. Mr Chan said that while the site would be properly preserved, the government's conservation experts had yet to arrive at a solution for other sites, including a lamp post near the Sam Shan Kwok Wong Temple on Ping Shek Estate in Ngau Chi Wan. 'We have been following the preservation of Tsang's works since his death and we kept trying different methods, but none of them worked,' Mr Chan said. He said that because of the sites' limitations, such as lack of space, it was not possible to build protective covers like the one at the pier. Other methods such as spraying protective coatings did not work either. 'It makes the surface go rusty because it traps moisture, which activates the corrosion process,' Mr Chan explained. 'But we welcome suggestions.' His explanation did not convince a friend of Tsang's, Lau Kin-wai, who has been campaigning for preservation of the sites. He said preserving them should not be too difficult for an organisation as big as the government. He said he would offer help while the debate over the artistic value of Tsang works continued. Meanwhile, he urged the government to protect the graffiti from further damage by the elements.