“To make a good painting, the most important thing is to sketch from life and nature,” he insists.

His limited mobility means he cannot go outdoors to paint any more. But even in his humble studio, he paints what he can see from his vantage point – even if these are the vases and pots gathered at the top of his cabinet.

Otherwise, he paints from memory – going over the same scenes and bringing fresh eyes to old subjects.

An intriguing middle section titled The World Outside ventures beyond Singapore – and beyond what casual art lovers know of Lim.

As a core founding member of Ten Men Art Group, Lim had made five art expeditions across South-east Asia and painted scenes from Bali to Brunei to Sumatra.

These trips had provided reprieve from his role as principal of the now-defunct Sin Min School, a position which he held from 1950 to 1981. There, he taught first in Hokkien, and then in Mandarin. He also taught art classes.

But less well known are his European travels.

In 2000, he did a residency in Paris organised by the Nanyang Academy of Fine Arts, during which he painted urban as well as pastoral landscapes. This included paintings of a mediaeval village in the Alpes-Maritimes department, south-east of France – the same places that inspired Western masters such as Henri Matisse and Pablo Picasso.

Shophouses (2000) and Dining Out At A Cafeteria (2000) both take urban Paris as their subject matter. But when the exhibition’s curator Jennifer K.Y. Lam casually asked the art handlers to identify the scene, she was intrigued that people perceived them as Singapore scenes – which led her to ponder about Lim’s relationship to home.

She says: “Could he have been missing home when he was spending the two to three months in Paris? I don’t have a hard answer, but I think it’s really nice to think of it that way, isn’t it?”

Ms Lam, who has been visiting Lim’s family weekly since more than a year ago, has also curated a display of never-before-seen materials from his home. These include reference books, scrapbooks and sketchbooks – objects that lend insight and credence to his oral history, which art historians primarily rely on today.

In one sketchbook on display, Lim lists six qualities of a good painting, including enigmatic entries like “quality of ethnicity, culture and nationality: lines” alongside sketches.

Ms Lam, a curator at the National Gallery Singapore who is in her 30s, says: “He has created his own visual dictionary.”