WASHINGTON: The loss-making US Postal Service (USPS) introduced Harry Potter stamps Tuesday, delighting fans of the fictional boy wizard but angering some philatelists who complain he's not American.

The limited edition of 20 stamps feature images of Scottish author J.K. Rowling's best-selling character “with the friends, heroes, villains and creatures that make up his world,” said USPS in a statement.

Pitched at collectors, the stamps -- unveiled at the Wizarding World of Harry Potter at the Universal Orlando Resort in Florida -- went on sale online and at selected post offices. “From improbable heroes and magical creatures to schoolroom antics and daring battles, the majestic Harry Potter stamps will inspire fans of all ages,” said USPS chairman Mickey Barnett.

Sales can only help the bottom line at USPS, which last week said it lost $5 billion in the fiscal year ending September 30, the seventh straight year in which it incurred a net loss, despite an upturn in revenue.

“I know what is going on the Xmas cards this year!!” said one fan on the official Harry Potter Facebook page overseen by Warner Brothers, which as owner of the film rights collaborated with USPS on the stamps.

Some stamp lovers, however, loathed the choice. “Harry Potter is not American. It's foreign, and it's so blatantly commercial it's off the charts,” said John Hotchner, former president of the American Philatelic Society, quoted Tuesday in the Washington Post.

“The attitude should be that stamps are works of art and little pieces of history,” echoed philatelic blogger Don Schilling, speaking to the Post. “They shouldn't be reduced to the latest fads, (to) whatever's going to sell.”

Other US stamps issued this year featured American musical icons Johnny Cash and Ray Charles, and civil rights heroine Rosa Parks, along with a puffin, bobcat, muscle cars, “vintage seed packets” and a Christmas Madonna and Child.