A Halifax illustrator has been nominated — again — for one of the most prestigious children's book illustration awards in the world.

Sydney Smith has been longlisted for the CILIP Kate Greenaway Medal for his 2019 book, Small in the City.

"I'm just very excited," Smith said. "You look at the winners from past years, and it's really intimidating to see yourself listed next to some of the greats, some of the most amazing illustrators through the golden age of children's books and picture books and to today."

Smith is one of 20 illustrators longlisted for the prize, which awards the winner £5,000 (about $8,800), plus £500 worth of books to donate to their local library, and a golden medal.

He won the award in 2018 for his illustrations in Joanne Schwartz's Town Is by the Sea, which depicts a day in the life of a boy in a 1950s coal-mining town.

Small in the City — the first book Smith has both illustrated and written — follows a young child's trek through a big city as they search for something they have lost.

It has previously won the 2019 Governor General's Literary Award and was on the New York Times list of 25 best children's books in 2019.

Smith, who grew up in Caledonia, N.S., said the book grew out of his experiences living in Toronto for six years. He said he was initially scared of living in the big city.

"I mean, growing up in Nova Scotia, you're kind of taught to fear the big city and also to distrust the big city. But when I got there, I just felt so much excitement," he said.

"For many years of living there, I felt small in the city. And then after a while you get used to it and you actually start to like feeling small in the city."

Smith said he believes the book resonates with readers because the traditional narrative structure hits a sudden twist.

"You expect it to be kind of light-hearted, but it ends up being rather poignant and full of emotion. It sparks empathy," he said.

"It offers a safe space for kids to explore emotions, especially emotions that don't necessarily have labels, like happy, sad. Kids experience a whole spectrum of emotions without having names for them, which is almost, I feel, a little bit more pure."

Smith said he started drawing as a young boy making comics and drawing monsters and superheroes. At one point, some family friends suggested he try using their paints, and he began exploring art more, eventually graduating from the Nova Scotia College of Art and Design.

In the early days of his career, he took any chance to showcase his work, making show posters for bands such as Hey Rosetta! and Down with the Butterfly.

"The bands would only pay 20 bucks, or you get free admission to the show or something, but it was an opportunity to show my stuff."

When he worked at the Halifax café Steve-O-Reno's and his boss asked him to make table number cards, he spent "days and days" on them, crafting ornately illustrated cards with pictures of birds on them.

"I'm sure he was expecting, just, you know, No. 1, No. 2."

Smith said when he and his wife decided to move to Toronto, he thought he might work in a coffee shop, or maybe an art supply store, but weeks before they left, he got an email from Toronto children's book publisher, Sheila Barry, asking him to work on a wordless book about a girl who picks flowers on the way home.

That book became Sidewalk Flowers, which went on to win a Governor General's Award and was also selected as a New York Times best illustrated children's book of the year.

"That book just changed my life because all of a sudden it launched my career into the stratosphere. I was being reviewed in the New York Times. I mean, I hadn't been really noticed anywhere," Smith said.

Smith and his family have now moved back to Halifax, where he is working on another book that he will both illustrate and write.

The CILIP Kate Greenaway Medal competition is judged by children's librarians, who select the nominees based on the artwork's ability to create an outstanding reader experience.

The short list will be announced on March 18, and the winner will be announced on June 16.