Wicked costume designer Paul Tazewell reveals the one thing Cynthia Erivo and Ariana Grande requested on set

It's already been hailed a "masterpiece" and a potential box-office blockbuster. To say that Wicked– the cinematic adaptation of the hit Broadway and West End musical – is one of the most hotly anticipated film events of the year would be an understatement.

The stellar cast, led by Cynthia Erivo and Ariana Grande, has attracted much excitement, and the outfits created by Oscar-nominated costume designer Paul Tazewell are sure to be just as celebrated.

"I would say that this is probably my biggest creative experience," says Paul, who had just completed work on Steven Spielberg's West Side Story when he embarked on the project, which took two and a half years.

Following the plot of the stage show, Wicked (which is in two parts, the second to be released next year) recounts the untold story of the witches of Oz: the gifted Elphaba (played by Cynthia), who is misunderstood for the colour of her skin and eventually becomes the Wicked Witch of the West, and Glinda (portrayed by Ariana), who is driven by her need to be popular and evolves into Glinda the Good Witch of the North.

The pair meet at Shiz University in the fantastical land of Oz and forge an unlikely friendship that will, eventually, be torn apart.

Intricate detail

Paul, 60, who lives in New York and whose credits include the Broadway production of Hamilton, was designing for eight months before shooting began in Elstree, Hertfordshire, where he worked with around 70 artisans across eight workshops.

His team, which included assistant designers and dyers, textile artists, hand embroiderers, knitters, beaders, pattern cutters, weavers and milliners, made around 1,000 costumes for both films, with 25 looks for Glinda alone.

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"You'd open the door to the Elphaba workroom and everything would be black and textured – a wonderful, mysterious place," Paul says. "Then you'd turn right and go through the door for the Glinda workroom and there'd be an explosion of pink.

"We had a warehouse space where there were thousands of people coming through, and racks and racks and racks of clothes from all over. It became its own event.

"When Cynthia and Ariana came in for some early rehearsals, we were full speed ahead."

They were both, he says, a "delight" to work with.

"I was with them for almost two years, having fittings daily. I needed to understand how they wanted to play these roles, and there's so much work that happens in the fitting room – looking at their body language and how they feel in a garment. I can't design in a vacuum; my work has to be brought to life by performers.

"But they're both clothing people," he adds. "They have their own sense of style, which was exciting to share. And they were courageous – we really pushed some extremes with how we were creating character."

As the film progressed, both actresses asked for higher heels.

"Neither is very tall, and it gave them a certain stature. I feel Cynthia wanted to feel that elevation as [her character] became more empowered."

The film mixes historic periods – from the turn of the century, when the original The Wizard of Oz book was written, to the 1930s Judy Garland film to the present day – "in the way that you see past silhouettes reflected in contemporary fashion", Paul says.

Painting with colour

The costumes of the two central characters had to reflect their contrasting personalities as well as their different journeys. Elphaba's colour scheme is black and grey and inspired by nature; Glinda is seen through a palette of pinks, lavenders and iridescent tones.

"The leading theme is that of opposites being attracted to each other. At first, they hate each other, but then they are put together in the same room and create a bond.

"Elphaba is a private, insular and protective woman who has been marginalised because of the colour of her skin. She's also an advocate for animals, so I thought it was important to connect her to nature and give her a more grounded feel."

Paul used textures and patterns taken from nature, including fiddlehead ferns and Fibonacci spirals, which are embroidered on to costumes made from wool and silk.

"Glinda is the big personality – effervescent and of great means. She's a young woman of artifice: polite, good and popular," Paul says.

"With Glinda, it's all an act; she's more of a politician."

The character wears a more historic silhouette – her skirt suit, for example, has a 1950s, Dior-inspired femininity – and much of her wardrobe features bubbles and butterflies. The standout costume is her "bubble" dress, inspired by Glinda the Good's dress in The Wizard of Oz.

Created from 137 pattern pieces and inspired by a Fibonacci spiral, the silk organza skirt was printed with a bubble pattern and embellished with bugle beads, iridescent sequins and crystals.

It took 225 hours to sew around 20,000 beads on to the pink bodice. "It was pretty involved," Paul says.

To read the full exclusive interview, pick up the latest issue of HELLO! on sale in the UK on Monday. You can subscribe to HELLO! to get the magazine delivered free to your door every week or purchase the digital edition online via our Apple or Google apps.