Titled The Cradle of the Chinese Ink Painting Movement, the five-day exhibition, which will open on Thursday, features 150 ink paintings by artists between 1969 and 1971, most of whom were in their early teens when they put brush to paper.

It was in Tam's art class that they were encouraged to freely express themselves through art. 'Back then, when it came to ink painting, the traditional method was to show the students how to copy famous paintings, or parts of a painting of their teacher,' says Tam. 'So instead of painting something that came from within, many students were expected to simply copy things like flowers or landscapes.'

Tam trained at the Northcote College of Education and was a qualified maths, English, physics and art teacher at Wah Yan College, Kowloon. 'Being a Jesuit school, it follows a liberal educational principle,' he says. 'They allowed me the time to develop this method I used in the art class - which was to allow the students to use traditional ink painting tools but to express themselves without copying older works.'

Tam says he enlisted basic mathematical principles such as the use of dots and geometric lines to help the students grasp the skill of manipulating the Chinese brush and ink, as well as the basic elemental concepts needed to understand composition. 'I was just experimenting with teaching. I never thought of it as amazing or revolutionary - the students were being engaged in observing and creating and of course asking questions. It was a great way to give their minds an exercise.'

The paintings lay undisturbed in the art storage room for a number of years until Tam received a phone call from the school janitor who said a renovation was due and that unclaimed items would be disposed of. 'I went to the school and saw a big collection of the paintings.' He grabbed as many as he could and took them home with him.

Looking at them, it is clear they are set apart from traditional ink paintings. 'I was a student of Lui Shou-kwan, who began pioneering the modern art movement in Hong Kong as early as the 1950s,' says Tam. 'He inspired me and I brought some of this into the classroom - it affected the manner in which I was teaching.'

Frederick Wong Tat-cheong, who now works with the government auditing service, says the exhibition is evidence of a novel and worthwhile approach to ink painting. 'When I saw my painting for the first time in over 30 years I couldn't believe it was mine,' he says. 'Mr Tam had to show me my name on it for me to believe it could be. I was almost 13 at the time, but today I am impressed with the quality. There are many other paintings better than mine.

'I never felt like I had any innate artistic ability. But this exhibition proves that with the right guidance, anyone can produce something beautiful.'

In addition to the exhibition, the organisers are publishing a book documenting Tam's teaching method, using the 150 paintings as illustrations, which they will donate to secondary schools in Hong Kong and on the mainland.

A seminar will be held on December 9 during which a panel of art educators will discuss the teaching method and paintings with Tam in front of an audience of secondary school art teachers.

Alice King, a member of the Ink Society, praises the exhibition. 'This will hopefully enable people to be more aware of the infinite possibilities when it comes to ink painting,' she says. 'It is anything but a dead art.'