Irving, indeed, has two tattoos. A maple leaf can be found on his left shoulder - the author of The World According to Garp and The Hotel New Hampshire is an American but he married a Canadian, and the leaf is for her. On Irving's right arm is a wrestling mat - of course, wrestling is his great passion and a recurring theme in his novels.
He became interested in tattoos while researching A Widow For One Year. Irving then conducted extensive research into tattoo culture for Until I Find You, visiting dozens of tattoo parlours. The central character, Jack, in Until I Find You has a tattoo artist for a mother and a tattoo addict for a father.