This far into Emerald City, you know that part of its visual appeal is due to the elaborate costumes. Glinda's (Joely Richardson) icy demeanor feels tangible through the screen thanks to her white cloaks; the women in the Wizard's (Vincent D'Onofrio) inner circle wear regal orbs and robes that make them seem equal parts holy and magical; West Witch (Ana Ularu) gives off the vibe of a cool, downtown chick in a rock band partially because of her bludgeoned-bob hairdo and man-repeller frocks.

Emerald City's costumes are eye-poppingly good, which should be expected: they're designed by Trisha Biggar, the acclaimed costume designer who did the costumes for three Star Wars films.

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But as is often the case with getting dressed, it's not so much what you wear that makes your outfit sing but how you wear it and how you accessorize it. And within Biggar's already outstanding collection of garments, one accessory stands out most: the magnificent masks worn by Lady Ev (Stefanie Martini).

Stefanie Martini as Lady EvStefanie Martini as Lady Ev

Lady Ev is the spoiled and demanding princess who begins a, shall we say, interesting relationship with Jack. From the moment we meet her, her face is hidden from view, for reasons that will become clear by the end of the 10 episodes. (And no, she's not disfigured.) What is evident right from the start is the level of detail, craftsmanship and imaginative design that went into making her pieces — 12 in all.

Stefanie Martini as Lady EvStefanie Martini as Lady Ev

"Ideas came from all sorts of places — lots of continents," Biggar told TVGuide.com exclusively from her home in Ireland. "Around the world, from antiquity to present day, people have been making and wearing masks. They're really universal. Almost any culture and on every continent, people wear masks for different reasons — ceremonial, theatrical, carnival, for personal transformations, concealment...so many reasons. It's been interesting to research."

Stefanie Martini as Lady EvStefanie Martini as Lady Ev

Yes the masks were comfortable. "Stefanie was incredible," Biggar said, because she had to use her eyes and body to convey emotion, giving the designer a new respect for the idea of the actor's body as an instrument.

Stefanie's comfort, as it happens, is part of the reason the pieces are literally priceless. Making them required scanning Stefanie's head and shoulders, then creating a replica of her in high-density foam. That model was used by at least 10 artisans in Budapest, Spain and other European countries skilled in metal, 3-D printing, jewelry, millinery (hat-making), leather, embroidery and bead work — making for a monumental effort across many hands, several countries and many hours that makes the real, full and total cost of the masks nearly impossible to quantify. And then there's the materials.

There's filigree metal — itself one of the most delicate, time-consuming materials whose process stretches back over millennia — plated metal, feathers, Swarovski gems, vintage lace, beads, felt, leather, shells and more. "Anything I could get my hands on," Biggar said. Later in the series, Lady Ev will be part of an event where many people are wearing masks — several hundred, all painted on by hand.

EMERALD CITY -- "Beautiful Wickedness" Episode 106 -- Pictured: Stefanie Martini as Lady Ev -- (Photo by: Rico Torres/NBC)EMERALD CITY -- "Beautiful Wickedness" Episode 106 -- Pictured: Stefanie Martini as Lady Ev -- (Photo by: Rico Torres/NBC)

As exhaustive as that sounds, Biggar said she enjoyed the process. "There were no boundaries," she said. "Really no particular period to be tied to, or country. Tarsem [Singh, director] loves costume and color and has a fantastic imagination himself. We had a great team. It was a lovely job."

Indeed it is. The masks beg to be displayed — much like her Star Wars costumes have gone on display in esteemed institutions, including the Smithsonian. As of now though, no such plans. Right now, they're in storage in Budapest. "I have no idea at this point if anything will happen with them or not," she said.

Emerald City airs Fridays at 9/8 c on NBC.