It's an art form that's used to push back against censorship, and it's happening at the Hamilton Public Library right now.

It's called "blackout poetry" — a form of visual and intellectual art that uses contentious books that have been banned in the past to create a piece that celebrates free expression.

These pieces are being created at the library's central branch as part of Freedom to Read Week, which is a national celebration of free expression, born of a protest against censorship that stretches back decades.

To create "blackout poetry," a participant takes a page from a book that is contentious or has been banned and "blacks out" the words they wish to cover up, leaving only the dominant words that speak to them on a deeper level. Artists at the library on Tuesday morning were using books like Margaret Atwood's The Handmaid's Tale, and Alice Munro's Lives of Girls and Women.

"In a way we are acting as the censor, we get to decide what we want to take out," said Erin Willson, public service programmer for the library.

Rallying against censorship is the heart of Freedom to Read Week, says Annie McClellend, the Executive Director at the Book and Periodical Council (BPC), which organizes the event.

"Intellectual freedom is the cornerstone to what makes our democracy work," she said.

Freedom to Read Week stretches all the way back to 1978 in Clinton, Ont., when the Evangelical Christian Church protested three titles: Margaret Lawrence's The Diviners, J.D Salinger's The Catcher in the Rye, and John Steinbeck's Of Mice and Men.

During this time, The Huron County Board of Education decided to ban Lawrence's The Diviners from five high schools within the region. This prompted the BPC to form its Freedom of Expression Committee later that year.

In 1984, the Book and Periodical Council launched its first Freedom to Read Week.

"Freedom to Read Week is a way to recognize intellectual freedom," said McClellend. "It's a way to talk about censored books and magazines here in Canada."

The organization says a few titles that have been protested in previous years that are being celebrated during Freedom to Read Week 2018 include Anthony Burgess' A Clockwork Orange, Mark Twain's Adventures of Huckleberry Finn, Phillip Pullman's The Golden Compass, and St. Stephen's Community House's The Little Black Book for Girlz: A Book on Healthy Sexuality.

Over the years, these titles were challenged by multiple groups of parents, educators, and churches, McClellend says, for reasons like inappropriate dialogue, mature themes, drugs and alcohol use, and acting out against religious beliefs.

Luckily, the local library doesn't tend to get requests from Hamiltonians asking them to pull any books from their shelves, says Lita Barrie, director of communications.

"Intellectual freedom is the key value for public libraries," Barrie said. "We always take advantage of this opportunity (Freedom to Read Week) to really acknowledge that, [We try to make our customers] understand the world around us and different peoples perspectives and intellectual freedom preserves the right to do that."