Quick, what’s your favorite iconic rom-com dress? Kate Hudson’s yellow silk gown in How to Lose a Guy in 10 Days? The red floor-length dress with the sweetheart neckline that Julia Roberts wears to the opera in Pretty Woman? The minidress from the makeover scene in She’s All That, when Rachel Leigh Cook walks down the staircase — and literally falls into Freddie Prinze Jr.’s arms — to the tune of “Kiss Me”?

Here’s another one to add to your list of faves: The show-stopping silk tartan Vivienne Westwood Couture Collection gown Brooke Shields wears in the holiday rom-com A Castle for Christmas. In the movie, Shields plays Sophie Brown, a bestselling author who’s in the market for a Scottish castle of her very own. That is, if she can get its owner, Myles the Duke of Dunbar (Cary Elwes), to part with it.

Shields, who was also an executive producer on the film, sought out the dress herself.

“We originally had a corset and a skirt as the outfit, and we just felt like we really wanted it to pop more,” Shields says. “And I went way out on a limb and found somebody that knew Vivienne Westwood. I just put a cold call in to their publicist and said, ‘Would this ever be a consideration for her to design it, and someone in the atelier to actually put it together?’ And it was miraculous what they came up with.”

The gown is now part of something even bigger. It carries on the long tradition of rom-com dress moments: the big reveal, when a character makes an entrance in a stunning gown, and the couple’s eyes meet. Shields describes it as “that perfect fantasy.” 

“I have one daughter who used to say she wanted to wear ‘dresses what touched the floor.’ And it’s from a romantic comedy she had seen,” Shields says of her daughter’s adorably grammatically incorrect turn of phrase. “She wanted the dress to go all the way to the floor. It was something from her childhood, and I think we all carry — well I do, anyway — we carry some of those Cinderella feelings from when we were a little kid.” We chatted with Shields about the little details that made the Westwood tartan dress so unique — and so perfect for her character in A Castle for Christmas. 

1. Yes, the dress has pockets.

Let’s be honest: Pockets are what everyone wants in a dress. “I didn’t put a lot of stuff in them, but just in case I needed a tissue or something, or a mint, there were little areas right in the side,” Shields says.

2. The dress is actually made up of three types of tartan.

“If you look at them, they’re subtle: One’s a darker green, and one’s a darker red. And the three of them are all woven together,” Shields says. “I felt like a princess. I mean, you’re in a castle in a dress like that? Come on!”

3. The corset was created with Scottish ceilidh dancing in mind.

The design of the dress’s built-in corset was taken from a vintage pattern, boning and all, but with a modern twist. “We said, ‘Look, there’s going to be ceilidh dancing,’ and we just needed it to be able to be functional,” Shields says. “So the corset was constructed in such a way that had a bit of elasticity to it, so that it wouldn’t dig in or pop when I moved.”

4. Bustling the dress was complicated, but that’s what gave it shape.

The gown’s custom-made bustle was its own intricate work of art. “There were parts, kind of like [in] a wedding dress, in the back that you could pull up and loop over a little button,” Shields says. “The bustle made it possible to dance, but it was like a puzzle: They had to bustle it so that it still looked really beautiful and was able to be danced in.”

5. The dress wasn’t exactly lightweight.

“It was a heavy dress. The tartan is silk, and there were layers and layers of it. There’s an inner corset, and then the outer corset… and there was another part in the back that sort of flipped over. So it was quite substantial, but it wasn’t uncomfortable.”

6. Wearing the dress helped Shields get in touch with her character, Sophie.

“Costumes are so important in transporting you to the essence of a character,” Shields says. “I’ve done enough Broadway work that it really just turns you into the character. But a lot of the time in film, you don’t always get the full effect of something like that dress. The reveal, even just for the crew, they hadn’t seen the dress, and they were just like, ‘Oh! Oh my God, it’s a beautiful dress.’”

7. When shooting outside, Shields wore a little something extra underneath the dress.

“I did have to wear leggings and long underwear when I was on the horse, because we were pretty cold,” Shields says. “And then in my close-ups, I was just wearing Uggs.” Staying toasty while keeping beloved rom-com traditions alive? That kind of dedication to love is always in fashion.