His work can sell for more than £15 million – but any experts from the Antiques Roadshow seeking to value one of Lucian Freud’s more unusual works might well be stumped.
For instead of working on a canvas, the painter - who attended a Dorset school, once tattooed an original image on the derriere of model Kate Moss using a technique he had picked up in the Merchant Navy.
After a lucrative career as one of the world’s most in-demand supermodels Moss, who lives in the Cotswolds, hardly needs the money, but she joked the tattoo could now be worth millions.
The supermodel posed nude for the painter when she was pregnant a decade ago and she has now revealed to Vanity Fair magazine that he etched two swallows on the base of her spine, which could now be worth millions.
Moss revealed that the painter had told her he had learnt to draw tattoos using permanent ink and a scalpel when he worked in the Merchant Navy during the Second World War.
Freud, who attended Bryanston School near Blandford Forum is one of the world's most collectible artists.
His painting of a naked sleeping benefit supervisor, made a record price for a living artist when it sold for £17.2 million at Christie’s in New York in 2008.
Moss said his portrait of her took nine months to complete, with the model sitting for the artist from 7pm to 2am. It was sold to an anonymous bidder at auction in 2005 for £3.9 million.