There was never any doubt that Nawapooh Sae-tang, the grandson of the late Bangkok-born artist Tang Chang, would inherit the family business of protecting and promoting his legacy.“My father had told me from a young age that as his eldest son, I would have to be involved in the running of the estate,” he says ahead of the May 1 opening of the Tang Chang Private Museum in Nakhon Pathom, an hour outside the Thai capital.It might not have been his choice, but Nawapooh has blossomed into a dedicated champion of his grandfather, who died in 1990, two years before Nawapooh was born.The estate has felt like something of a ball and chain for the family ever since Tang chose his fourth son – Nawapooh’s father, Thip – to manage his affairs posthumously. The burden also fell heavily on Nawapooh’s mother, Duangnate, who had to navigate all the English-language communications in the early days.“My father was working in a publishing house,” says 34-year-old Nawapooh, who is unassuming and sports the same sharp buzz cut as his 63-year-old father. “Nobody wanted [the archive], but my grandfather told everyone before he died, ‘This is for Thip.’”An undated photograph shows Tang Chang with his wife and two children outside their home in Bangkok, Thailand. His pseudo-calligraphy, which is illegible, can be seen painted on the door beside them. Photo: Tang Chang Private MuseumThe responsibility Thip and Duangnate shouldered in their twenties was staggering – the sheer volume of material they inherited was onerous, to say the least.