Inside my visit to Warner Bros’ Harry Potter costume workshop: Mastering the Magic

What is Mastering the Magic at Warner Bros. Studio Tour?

A brand new feature launching this spring at the Warner Bros. Studio Tour is the exclusive workshop Mastering the Magic. Until now, it was reserved for schools taking part in the Studio Tour’s educational programme, but for the first time it is open to the wider public, much to fans’ delight.

The workshop takes place in an underground area of the studios, accessed via lifts designed to resemble those used in the Ministry of Magic. We were first treated to a delightful afternoon tea, with a particular highlight being the mini chocolate cakes shaped like Professor Pomfrey’s mandrakes, alongside a wide selection of finger sandwiches and sweet treats.

After enjoying the delicious spread, we made our way to the workshop room, which focuses on costume design. Here, well-guarded secrets from the Harry Potter films are revealed, and participants are given exclusive access to original costumes. It’s also a rare opportunity to see the creative process that brought the very first designs to life, from initial sketches to the finished pieces that helped define the wizarding world.

The Warner Bros. costume workshop is led by experts who work at the heart of the studios, sharing behind-the-scenes anecdotes even I hadn’t heard before. This made the experience all the more fascinating, highlighting subtle details rarely noticed and giving us the chance to see some of the films’ most iconic costumes –  from Snape’s not-so-black robes to Luna’s Christmas dress, and even Hagrid’s enormous trousers. We also got to see sketches and mood boards created by the designers, revealing their step-by-step process for bringing each costume to life.

What you’ll discover inside the new costume workshop

The Harry Potter costume workshop takes us on a deep dive into the art of costume making, from the very first sketches to choosing colours that help define a character’s identity across all eight films, to selecting patterns and textiles, and finally seeing the completed costumes. As this year marks 25 years since The Philosopher’s Stone hit the big screen, we were lucky enough to see some of the original costumes from the first film, including the school uniforms and Quidditch gears. We learned how every fabric, colour tone, and particular style or cut contributes to a character’s presence on screen, often highlighting details that are barely noticeable but essential to bringing them to life.

Iconic Harry Potter costumes up close

Seeing some of my favourite characters’ outfits up close was truly magical. I was stunned to discover the real colours of Professor Snape’s suit (no matter what anyone says, Snape will always be the true unsung hero), as well as Luna’s sparkling Christmas tree dress, and learning the secrets behind how these two iconic costumes were made. I was gobsmacked to hear that, contrary to popular belief, Snape’s robe – so perfectly dark and fitting for the Half-Blood Prince – is actually a deep navy blue. The choice makes perfect sense: Snape is often seen in dimly lit spaces, from potion classes in the Hogwarts dungeons to patrolling corridors at night or attending Death Eater meetings. The robe itself is surprisingly heavy, designed in the style of Victorian and Dickensian schoolmasters, adding to Snape’s commanding presence.

When it comes to standout costumes, we were lucky enough to see Hagrid’s massive trousers up close – their sheer size left us momentarily stunned, with three of us in the workshop able to stand behind them and almost disappear! I had no idea that the production had the costume and design teams create two versions: one for Robbie Coltrane and one for his stunt double, perfectly sized to reflect the Hogwarts gamekeeper’s enormous proportions. Since Hagrid spends most of his time outdoors caring for magical creatures, his costume had to tell that story, with the team roughing up the fabric, adding dirt and holes as if one of his beloved pets had been at it.

The craftsmanship behind the magic

Hagrid’s towering presence on screen was brought to life through a clever mix of costumes, prosthetics, and camera tricks. At the workshop, we got to see his oversized trousers and the giant prosthetic mask worn by Robbie Coltrane’s stunt double, former England rugby player Martin Bayfield, along with a padded suit underneath to create the illusion of the half-giant. It’s now much clearer how filmmakers made Hagrid appear so enormous, in addition to post-production effects. Described in The Philosopher’s Stone as twice the height and three times the width of a normal human, Hagrid’s size was achieved through a combination of techniques: hiring a large double, using oversized sets and props, and filming from carefully chosen angles.

The design team crafted large-scale objects and props for Hagrid, and smaller versions for other actors in the same scenes to maintain the illusion. During the workshop, we even saw two versions of Harry Potter’s pink birthday cake – one large, one small. A standout prop was Hagrid’s prosthetic giant head, astonishingly lifelike from skin tone to facial hair, which Bayfield wore on set when standing in for Coltrane. The staff even shared a few secrets about which scenes feature Hagrid’s stunt double if you watch closely – I think a rewatch is definitely in order!

Create your own Harry Potter-inspired costume design

While the experts were on hand, guiding us through the racks of original costumes, I was able to request up-close looks at pieces that caught my eye and ask questions before returning to my table. There, I could choose from a selection of fabrics, from furry textures to satin and shimmering patterns, adding to the sketch I had made for my own design. It felt like I was in the very room where those costumes were first imagined, crafted purely from creativity and imagination.

Using the concepts and steps the designers follow, I brought my own creation to life: picking colours and fabrics to match my character’s personality, experimenting with velvet, fur, and red silk – a combination that felt perfect for one of Durmstrang’s students.

How Harry Potter costumes were designed

Bringing these characters to life starts with the script. Costume designers read character descriptions and note any standout features, which gives them an early sense of what each costume should look like. Take Hagrid, for example: he’s described wearing an oversized coat, from which he pulls a kettle, a frying pan, sausages, a pink umbrella, and a paper box containing a chocolate cake. That alone immediately tells you his coat needs plenty of large pockets!

The next stage involves creating mood boards. Our hosts explained that after collecting all the details from the script, mood boards help visualise the costume and capture key inspirations for each character. These can include magazine clippings, colour palettes, textures, and other references that reflect the character’s personality, complexion, and story arc. For instance, Harry Potter, who mostly just wants to be Harry, is dressed in muted blues and greys for his hand-me-down clothes, signalling how poorly he is treated by the Dursleys without drawing attention to himself.

Then come buyer boards, which show how the costume budget is allocated. As with any movie production, each character has a specific portion of the costume budget based on their importance and wardrobe needs. Someone like Lucius Malfoy wears rich fabrics from high-end stores, while Hagrid, being a half-giant, can’t exactly pop down to a shop – his clothes are crafted from specially sourced materials to suit his enormous size.

Why Mastering the Magic is a must-see experience

• See some of the most iconic costumes from the films: Take a close look at the designs that brought the wizarding world to life, from Luna’s Christmas party dress, which is carefully hung upside down to keep its tree shape, to Sirius’s coat, which shows its Animagus form.
• Discover some behind-the-scenes secrets: See how the fabrics were chosen, colours selected and textures aged or distressed to reflect the different characters' personalities and backgrounds.
• Explore the original sketches and mood boards: See how the designers turned their ideas into ready-to-wear costumes, step by step.
• Hear exclusive anecdotes from the experts: Hear stories that you won't find in any book, covering everything from wardrobe mishaps to clever design tricks.

Plan your visit

It’s highly recommended to book in advance, as Mastering the Magic: Costume Creation runs on select dates throughout March and April and spaces are limited for each session. The experience begins at 3pm with a delightful afternoon tea, followed by a 45-minute workshop led by a costume design expert, and then full access to explore the Warner Bros. Studio Tour London.

During the current Magical Mischief feature, you’ll also discover how some of the films’ most chaotic moments were brought to life – from the Weasley twins’ unforgettable fireworks during their O.W.L.s exams to the clever trickery behind Dobby levitating a cake straight onto Aunt Marge’s head. A personal highlight? Seeing the Cornish pixies run riot in Lockhart’s classroom, tormenting poor Neville Longbottom – a true classic.

And if you’re planning for an extensive visit, have a look at our guide on how to visit the Warner Bros. Studios and make time for some of the tour’s unmissable highlights, including Professor Snape’s Potion classroom with its bubbling cauldrons, the cosy Gryffindor common room, and Dumbledore’s fascinating office.

A first look at Mastering the Magic

Being invited to the exclusive preview of the new Mastering the Magic workshop at the Warner Bros. Studio Tour London felt incredibly special, feeling like stepping into a chapter of the Harry Potter that hadn’t yet been written. What I loved most was being able to see the costumes up close and hear anecdotes I’d never come across before – and trust me, I know a fair few! Discovering what went on, both on and off set, and learning about the creative process from script to first sketches to final designs was absolutely fascinating. It’s an experience I would recommend to any Potter fan or cinema enthusiast.

If I had one tip, it would be this: make the most of every minute. Be curious and ask those questions that are burning your tongue. Step closer to the costumes and really look at the details. Learn about the ideas that defined the films’ most iconic characters and allow yourself to tap into that same creativity. It’s not just a workshop, it’s a chance to see how imagination was transformed into the magical world we all grew up watching on screen.