A birthday card drawn by artist Lucian Freud is coming to a Christie's auction next month with a top end estimate of £6,000.
The self-portrait, which also depicts Freud's mother, is thought to have been created in 1941 when the budding artist was 19, eight years after the family left Germany.
The birthday card, which features a border of small animals, was created with gouache, ink and coloured pencil and measures less than seven square inches.
It is not known how the consignor acquired the piece, which goes to auction on April 20.
The 88-year-old artist used his mother as a muse for 20 years, his last work, The painter's Mother Dead, produced on the day she died in 1989.
"I started painting her, because she'd lost interest in everything, including me," Freud explained.
"Before then, I always avoided her because she was so intuitive that I felt my privacy was rather threatened by her."
Freud's work is popular with investors and can command huge sums at auction. The 1995 piece Benefits Supervisor Sleeping achieved £20.5m at a Christie's sale in 1997.
A triptych of Lucian Freud by friend and fellow artist Francis Bacon sold for £23m at a Sotheby's auction in February.