Superheroes and Spanish royals in opera costume sale

Superheroes, fairies and Spanish royals are set to unleash a swarm of locusts on an inner-city warehouse.

Opera Australia's clearance sale returns for the first time in more than five years, opening its doors over two days in April.

Wigs and wardrobe manager Rebecca Ritchie promises there will be something for everyone.

"The first sale that we did, one woman found her wedding dress that was an old Aida dress. She said she'd never felt more glamorous in her life," she tells AAP.

"Remarkably, black capes seem to be a big attraction. It's something to do with Star Wars or Batman or little boy fantasies - they tend to love a sweeping cape."

Handmade garments on sale come from previous productions including Carmen, Don Carlos and The Pearl Fishers.

"It's a real mixed bag. We're not selling off particular whole shows, and it's the first time we've done fabrics and trims," Ms Ritchie says.

"So there's certainly something in there for the home sewer or someone wanting to decorate their house with fake fur."

Most items, including vintage clothes to hats, are priced between $10 and $20, with fabrics and trims as low as 50 cents.

Elaborate pieces like fairy costumes and period clothes will be sold for more than $100.

Opera enthusiasts will recognise items worn by fan favourites and anti-heroes.

Ms Ritchie says the last sale in 2017 was a smash hit.

"By the end of the day, the room was empty and it was like locusts had gone through," she said.

"We had a queue that stretched around the block and hundreds of people come through. I don't think I stopped all day."

The sale will take place at The Opera Centre in Sydney's Surry Hills on April 14 and 15.

Shoppers are advised to get in early and wear leggings.

"If you want to try things on, you'll have to do it over your own clothes," Ms Ritchie says.

"And bring bigger bags, bigger thank you think you're going to need because our costumes are quite large.

"It's not like going dress shopping."