Canada’s Financial Post covers the sale of Group of Seven artist Tom Thomson’s work with a distinctive and ironic notation on the back of the canvas. (All prices are in Canadian dollars):

Tom Thomson’s painting Winter Morning, made famous by the words “Not for sale” scrawled across the back in the handwriting of Lawren Harris, fetched $973,500 at auction last night, one of the highest bids ever for a Thomson painting. […]

“There were multiple bidders, probably about three or four bidders on the work,” he said. “It was feverish bidding the moment it opened.”

The painting is unique not simply for what is painted in Thomson’s trademark brush-strokes, but for the collection of markings on the reverse — small notes that help paint a picture of previous ownership and interest in the artwork, including Harris’s underlined instructions not to sell the piece.

“Tom Thomson paintings have jumped in value over the last several years, so as an investment people are attracted to that,” Mr. Cowley said.

A Thomson painting of a similar size sold for $1.96-million at Sotheby’s Toronto in June 2008.

Thomson’s painting style is said to have influenced a group of contemporaries who became known as the Group of Seven, of which Harris was a member. Thomson drowned in July 1917 during a canoe trip on Canoe Lake in Algonquin Park.