Dad and me, swimming

Melanie Andrews was eight when her father, artist Michael Andrews, portrayed them both swimming in a Scottish rock pool. The painting, Melanie and Me Swimming (1978-9), has since become one of Tate Britain's best loved images and top-selling postcards.

Melanie has her own explanation for its popularity: "I think people wish they'd had a relationship like that with their father. A friend of mine is a prison visitor and takes all sorts of postcards with her, but it's that picture which everyone wants to talk about."

Today Melanie is 31. Her father died six years ago, aged 66, and a retrospective of his work opens at Tate Britain on Thursday.

Andrews is the least known of the School of London artists - a vague term coined by RB Kitaj in 1976 to describe his figurative work and that of other artists in his circle, such as Frank Auerbach, Francis Bacon and Lucian Freud.

Freud taught Andrews at the Slade School of Art and Andrews met his wife, June, at a party at Freud's house in 1958; she was then head hostess at Churchills nightclub, just as Christine Keeler and Mandy Rice-Davies were emerging onto the scene.

Melanie, Andrews's only child, spent her first seven years in London. "We had David Hockney next door, he'd teach me how to cheat at conkers by baking them in the oven. Lucian Freud would come for Christmas every year and insist on watching The Wizard of Oz after lunch every time - I still can't bear that film. There were so many artists in the studios where we lived that it was just my environment and it didn't feel weird."

Andrews's friendship with Freud and his set is the subject of much of his best-known work, particularly his 1960s portraits of the louche Colony Room set, named after the celebrated Soho drinking club which was the haunt of Bacon, Auerbach, Freud and John Minton. So the tranquillity of Melanie and Me Swimming, a little girl supported by her father as she takes her first strokes, may come as a surprise.

Andrews worked extremely slowly, spending on average 12 to 18 months on a painting - often one of a series - and Melanie and Me Swimming was no exception.

"Dad was incredibly precise in everything he did," Melanie says. "He wanted you to feel that you were in the painting with him, that's why he painted so big."

Melanie and Me Swimming came at a time of transition in the family's life - it was started the year after they moved to Geddeston, on the Norfolk/Suffolk border, where Andrews had grown up - and perhaps that is why Andrews makes a rare appearance. In his portraits of life at the Colony Room he preferred to remain an observer.