Artist's mini-masterpiece on a Post-It note fetches £640

Office-workers may find themselves doodling a little more carefully on that little yellow pad this morning. Yesterday, a few carefully executed pastel and charcoal lines transformed a humble Post-It note into a £640 work of art.

Office-workers may find themselves doodling a little more carefully on that little yellow pad this morning. Yesterday, a few carefully executed pastel and charcoal lines transformed a humble Post-It note into a £640 work of art.

The world's most valuable yellow "stickie", now renamed After Rembrandt, was created by the artist R B Kitaj as part of an internet auction to raise cash for charity.

His mini-masterpiece beat off competition from less conventional artists, including a £235 bid for a miniature work by the Animal Hospital presenter Rolf Harris - known for his creative efforts with a Stylophone - and £100 for a creation by the TV artist Tony Hart.

American-born Kitaj, whose entry in the 1997 Summer Exhibition at the Royal Academy had a price tag of £1m, was among the prominent figures who donated their time andtalents to create a set of mini-masterpieces for the auction.

His contribution was snapped up by Philip Hodgson of Nottingham who placed his bid just before Christmas on the last day of sale.

Guinness World Records has now declared the price has made it the world's most valuable Post-it note. The manufacturer, 3M, held the sale, which has raised £5,000 for Barnardo's and the Royal Academy schools, to mark the 20th anniversary of its notes.