When Elizabeth Houghton Barden opened Broad Ripple’s Big Hat Books in 2005, she didn’t expect to end up with an in-store collection based on her shop’s namesake.

But that’s exactly what happened, thanks to her customers.

There are about 20 hats — including a firefighter’s helmet, a Victorian-looking ladies’ topper adorned with feathers, and a Harry Potter-style Hogwarts hat — all perched on bookshelves inside Big Hat Books. Barden said there’s another 15 that aren’t on display, yet.

“It is funny that it took on a life of its own,” she said. “That’s the part that is magical to me.”

The hat collection began when Barden received a stack of George Crile’s book “Charlie Wilson’s War” and complained to customer Tom Hipple that it wasn’t selling in the store, although it was doing well outside of Indiana, she said.

In an effort to help Barden sell copies of the book, Hipple brought in a hat for good luck; Barden put it near the cash register. A short time later, news came that Tom Hanks would star in a movie based on the book, and Barden said book sales started to pick up.

“People just started bringing (hats) in after that,” she said.

Barden doesn’t know where some of the hats are from. “They leave them on the front door,” she said of the anonymous donations she sometimes receives.

So far, one has been stolen. A sorting hat from a Harry Potter film, which was given to her by a friend who worked on the movie, disappeared.

Of course, inspiration for the customer-fueled hat collection came from the 2,700-square-foot Cornell Avenue store’s name, which Barden said has several origins.

“We (she and husband Dan) struggled with the name,” Barden said. "It needed to be simple and clear and tell something about how we feel about a story.

“And every hat, I think, comes with a story.”