The thing about Canadian art is that Canadians have largely kept it to themselves — so says British art historian Ian Dejardin.

But there's definite potential for worldwide appreciation of Canadian art, and tonight could mark one instance where the cat's out of the bag.

The commanding large-scale canvas Mountain Forms by iconic artist and Group of Seven founder Lawren Harris — a vibrant Rockies scene from his coveted 1920s creative period — hits the block with Heffel Fine Art Auction House in Toronto. The work depicts Mount Ishbel, which is in Alberta's Sawback Range in Banff National Park, east of Johnston Canyon.

Tapped with a conservative presale estimate of $3 million to $5 million, the painting is expected to sell for more.

If it crosses the upper threshold of the estimate, it would likely become the most expensive Canadian artwork ever sold at auction, knocking off longtime record-holder Paul Kane's Scene in the Northwest. Harris works already take up three spots among the top five most valuable Canadian artworks ever sold at auction.

'It's about time you could see a Lawren Harris at the Tate or the National Gallery in London,' says Dulwich Picture Gallery director Ian Dejardin, who takes over as head of the McMichael Canadian Art Collection in April. (CBC)

The audience for Canadian art is out there, says Dejardin, pointing to his own experience at London's Dulwich Picture Gallery, mounting critically acclaimed exhibitions on Tom Thomson and the Group of Seven as well as Emily Carr — shows that introduced Canadians to many new admirers, inspired lengthy queues, drew raves from attendees and also moved on to other European galleries.

Lawren Harris is such a powerful and attractive artist. He is someone who is ripe for appreciation abroad. - Ian Dejardin

"People still talk about the 'Lawren Harris chapel,'" recalls the Dulwich director, describing how one gallery space was transformed into an introspective chamber of dark blue walls bearing Harris' Arctic landscapes and icebergs during the Painting Canada show in 2011.

A more recent example of how Canadians are seeping into the international art consciousness? A Carr piece turned up alongside iconic artist Marcel Duchamp's artwork in an issue of the Tate gallery's influential art magazine.

"That's an extraordinary thing to see. And no one would have thought of that before we had that exhibition here," Dejardin says, referencing the 2014 Dulwich exhibit From the Forest to the Sea: Emily Carr in British Columbia.

Harris, recently celebrated in the high-profile Steve Martin-curated solo exhibition in the U.S. and Canada, "is such a powerful and attractive artist. He is someone who is ripe for appreciation abroad, particularly in the States, where they have the comparison with someone like Georgia O'Keeffe" — an "international superstar" whose work recently packed crowds into the Tate Modern, according to Dejardin.

"Lawren Harris deserves to be seen in the same breath, I think, as that," he says, adding: "Tom Thomson could be the next global, van Gogh-like superstar if Canada puts its weight behind him."

Some of Canada's most iconic artists, like Harris, left, Emily Carr and Tom Thomson, are ripe for for greater appreciation abroad, says Ian Dejardin. 'Tom Thomson could be the next global, van Gogh-like superstar if Canada puts its weight behind him.' (Canadian Press)

Though auctions are "notoriously difficult to call" and the global art marketplace "a curious planet to live on," Dejardin, slated to take over as the new executive director of the McMichael Canadian Art Collection in April, feels more international awareness of and interest in buying Canadian art would be a healthy development.

"The day when people start bidding internationally for Canadian art will be a good day, I think, generally for the appreciation of Canadian art in the world. It deserves it," he says.

"It's about time you could see a Lawren Harris at the Tate or the National Gallery in London. They buy Scandinavian art, for instance — why not Canadian?"