Of course, it's Rowling's imagination that conjured up young wizard Harry's description — black, unruly hair; green eyes behind glasses, and, don't forget, that scar on his forehead, courtesy of You-Know-Who. (If you Don't-Know-Who, you probably won't be reading this article anyway.)

But it was GrandPré, 51, of Sarasota, Fla., who has been drawing Harry for the cover of each blockbuster book, as well as creating the illustrations that come at the start of each chapter. She's drawn him from a boy of 11 in book one to age 16 in book six.

"It's a challenge to take a character ... and make sure he ages correctly and make sure he looks like he would look if he were to get a year older," she told the Associated Press. "I feel like I'm his mom, I comb his hair or I mess it up, I make sure he looks good before he goes out the door."

GrandPré, who has been illustrating books for 15 years and working as an artist for 25 years, had no idea what she was getting into when she got the call from Scholastic, Rowlings' American publishers, about creating the art for the first book. She asked to read the work, to see if it would be a good fit. (She still gets to read each book before creating the art, making her one of the few people in the world who has actually read book six already! Don't bother asking her what happens, she won't tell you.)

GrandPré loved what she read. "It's like a candy store for an illustrator," she said. "I connected with Harry pretty quickly and loved the way J.K. described everything. She's such a visually thinking person. You can't pass that up."

GrandPré created the art the way she has for each subsequent book — going through the story with a highlighter, picking out descriptions. Then comes the sketches, different ideas for the cover and chapter art. "I go through a lot of tracing paper," she said. "I re-draw and re-draw." GrandPré calls her style "soft geometry" and uses a combination of straight lines, sharp angles and curves to create her colorful images.

Working with layers of pastels on paper, GrandPré creates the artwork she wants and send it off to the publishers. She's careful not to create anything that's too obvious — she just wants to drop some hints to the reader, not tell them what happens next. "I get to show the reader the essence of the book without giving anything away," she said. "I kind of tempt the reader to keep moving on through the book." As the books have changed, getting darker in tone, so has her palette, from a lighter combination of colors in book one to shades of blue for book five.

One thing she doesn't do is discuss anything with Rowling. Scholastic would show Rowling the images as they were being created, but the two never collaborated. GrandPré did get to meet her, during a visit Rowling made to the United States. "She was really great and showed a lot of appreciation for my work," GrandPré said.

The Harry Potter series has been a global publishing phenomenon, and boy, does GrandPré know it.

"It takes a lot of focus to work on this project, it's a bit high-pressure," she admits. "I don't know that I would want to work on another one of this magnitude."

But she's also loved it, and is bittersweet about the cover for the final book seven.