If you happen to bump into Batman, Superman or Spider-Man this weekend then make sure you join them to score a free comic book.

International free comic book day will be held on Saturday at the Invercargill City Library and attendees are encouraged to dress up as their favourite superhero to help celebrate the day.

And there is even an incentive for doing so, with people in costume receiving an extra free comic book as reward.

Event co-organiser Tania Hartnett said it was the fourth time she and her husband Leon had helped put the event together.

She said 1000 comics would be distributed on the day.

"We've got friends of our kids who struggle with dyslexia and reading and comic books and graphic novels was a way for them to find a passion for reading. It's a skill to read graphic novels and comic books. It requires a different processing in the brain so there are benefits for people being able to read them as well."

Comics are sourced from an overseas distributor and shipped to Invercargill for the day.

Mee & Henry Law Ltd helped sponsor the event by paying for the comics and freight.

People who attended would be given a comic, with additional comics given to those who dress up as well as people who donate a non-perishable item to the Salvation Army.

A maximum of two comics per person would be given out.

Mrs Hartnett said they hoped to give out all of the comics.

"It's a tricky job for us to select the comics because there are 50 titles to choose from. So because we're aiming mostly for younger people we try and pick more all age suitable for children and teenagers, and then we get a small selection that do older teens and young adults."

She said in the past people as old as 70 had shown up requesting a comic and people from keen comic fans to those who have never read one would attend the day.

The event runs from 10am to 12.30pm.

In keeping with the comic theme, those taking part in the weekly Invercargill parkrun at Queen's Park are also encouraged to dress as their favourite Star Wars or comic book character on Saturday. Participants are asked to bring a non-perishable food item to be donated to the Salvation Army Food Bank. These will be added to the collection at the library.