Artists put students in the picture: Masterclasses at Dulwich give young talent the chance to refine artistic skills. Elaine Fogg reports

Young Londoners are being tutored in the finer points of painting and drawing at Dulwich Picture Gallery. The scheme gives students aged 11 to 23 the chance to improve their technique by working alongside acclaimed British contemporary artists. Results from the project, paid for by a pounds 10,000 Sainsbury Visual Arts Award, will be reviewed back at school or art college.

Last week Sarah Raphael, whose work hangs in the New York Metropolitan Museum of Art and London's National Portrait Gallery, temporarily abandoned her Camberwell studio to tutor 20 teenagers from Burntwood school, an all-girls comprehensive in Tooting. She is one of a pool of artists taking part: others include Graham Crowley, Michael Kenny and Eileen Cooper.

Ms Raphael, daughter of author Frederic Raphael, is a figurative painter. She has been compared with Turner and Cotman and is known for her landscape, portrait and imaginative narrative work.

Despite the praise directed her way - the critics admire her use of light and shadow, and the skill and simplicity of her compositions - Ms Raphael admitted being daunted by the thought of teaching youngsters.

'I decided to work with kids because I was asked by my agent, Agnew of Old Bond Street. I said I would do it as long as the kids are serious about it and there is no mucking about. To start with, I asked the class: 'Draw something that reminds you of something in yourself.' I wanted to give them some idea of light in the paintings and how to work with the light source.

'I wanted to teach them that if you look behind the figure or object, the object will come out. I tried to put forward the idea that the paintings are basically tonal and not linear. I wanted to convey the idea that you can change things, providing you know where the light source is and providing that light source is consistent.

The pupils, ensconced among the gallery's collection of paintings by the great masters of the 17th and 18th centuries, mostly chose to copy paintings depicting suffering - perhaps because many were awaiting examination results.

Beatrice Sackey, 18, who wants to complete an arts foundation course at South Thames college, had chosen Antonio Bellucci's St Sebastian of Faith and Charity. 'I'd never really thought about using light and tone. I was just used to drawing lines. That's what it's all about, about light and shadow and how it hits the subject.

Ms Raphael said: 'Beatrice's work is really passionate. A miracle happened at 2.30pm. Everyone got the message. I had begun drawing for them and suddenly it became a real pleasure to see results. One girl, Zita, turned in an exceptional piece of work.

On a settee, Sarah Chowdry, 16, had been fine-tuning the body of St John, drawn in charcoal and pencil and taken from Guido Reni's St John the Baptist in the Wilderness.

'I had just done the body and it did not look very real. Sarah came round and showed me how to darken the bit behind the body to make it stand out more.

Linda Weyer, their teacher, looked on proudly. Her pupils had not let her down.

Ms Raphael said: 'I've taught post-graduate students before, but never a class full of teenagers. They responded really well and at the end of the day were quite chuffed.

Married to Nicholas McDowell, a marketing director, Ms Raphael has two children, Anna, aged four, and Natasha, seven. As a child she was allowed to make a mess, to get paint in her hair and on walls. She is sceptical about hot-housing. 'You can give children certain technical hints if they are ready, but if it's done too early it can really bugger them up. What's horrid is that if you give them too many constrictions it can do them harm.

She learnt much as a Camberwell Art School student, but says: 'Suddenly, I became incredibly pretentious. Before that, I was painting prisoners with pickaxes. . .anything that took my fancy. While you do have to teach people art, I feel if you are too reverential they start imitating great art, badly.

Ms Raphael is finalising a show based on work completed in Australia, part of a Villiers David Foundation grant. 'I am doing the desert from memory. The laws of light in the bush are very particular. You have to internalise them.

Dulwich Picture Gallery, College Road, SE21 7AD. Open Tues-Fri 10am-5pm, Sat 11pm-5pm, Sun 2pm-5pm. Free Fri and for under 16s. Others pounds 2.

(Photograph omitted)