TORONTO -- Canadian designer John Muscat had no idea he was going to be part of one of the biggest stories of the year.

The fashion brand Line the Label got priceless exposure Monday morning when a white wool wrap coat Muscat designed with Jennifer Wells was worn by Meghan Markle during the photo-op for her engagement to Prince Harry.

"I was as surprised as everyone else," Muscat said in an interview.

"I think it's really quite amazing of her to bring a bit of Canada to London, and to share this incredibly special day."

By the time he got to work around 9:15 a.m., the white coat, which Line the Label renamed the "Meghan," was already sold out. It's still available in a rose dust colour for $799, and Muscat said the white version will be back in stores in early March.

Markle, who is from Los Angeles, has supported many Canadian designers since she moved to Toronto in 2011 to film the TV series "Suits." She's worn pieces by high-end designers like Jason Wu and Erdem and partnered with the retail chain Reitmans for an advertising campaign and a "capsule collection" in 2016.

Fashion journalist Jeanne Beker said she was "thrilled" to see Markle choose a Canadian designer for the photo op -- she also wore an emerald-green dress, nude crisscross pumps, and earrings by Canadian jeweller Birks -- in part because she knows the significance of that kind of coverage.

"I spoke to her last year when she launched her collaboration with Reitmans, and she told me that she wished that Sophie (Gregoire) Trudeau would consider wearing one of her dresses," Beker said.

"It's funny to see how things have changed, how she's in the power position of wearing a label that she could end up doing something fabulous for."

Muscat thinks Markle's affection for Canadian designers was a natural extension of her life here.

"I believe that she became part of the city, and she really fell in love with Toronto," he said.

"The brands that were here were something that she wanted to support. I feel like she was an adopted Canadian."

Markle has been pictured wearing clothing by Toronto-based designers Smythe and the luxury outerwear label Sentaler, also a favourite of Kate Middleton's.

Designer Bojana Sentaler, who founded the label, said it's been exciting to see Markle champion Canadian fashion.

"We're lucky, because she did build relationships with the Canadian fashion industry, and she's been so supportive," Sentaler said.

The actress first visited Sentaler's Toronto showroom several years ago and has continued to wear their pieces. There's already been a huge surge in demand for a grey alpaca wrap scarf Markle wore in London just a few days ago, Sentaler said.

Earlier this year, Markle was seen at a wedding with Prince Harry in Jamaica wearing a floral maxi-dress by Erdem, the label run by Canadian-Turkish-British designer Erdem Moralioglu. In a Vanity Fair cover story in September, Markle said she'd been wearing the designer's clothes "for years."

Not all of her Canadian fashion choices have been at such elite price points. Markle attended the opening ceremony of the Invictus Games wearing a mid-length maroon chiffon dress from Vancouver-based retailer Aritzia, which retailed for $185. She paired the dress with a matching leather jacket by Montreal outerwear brand Mackage.

"I think that accessibility is something that's very important to her," Beker said, referring to the Reitmans line.

"People saw her character Rachel on the show 'Suits' wearing very expensive designer clothes, and she knew most women couldn't afford that."

Markle made an effort to "give us style that is relatable as well as inspiring," she added.

Given her past collaboration with Erdem, and his connection to both Canada and the U.K., several high-profile voices in the fashion world have started to speculate that Markle might consider the brand to design her wedding dress.

"Wouldn't that be great?" Beker mused.

Whoever designs the gown, Beker said it will likely be modern and elegant.

"Meghan's known for her no-nonsense sense of style," she said.

"Very understated, very chic. I don't see her as one of these girly girls who's going to wear something too frou-frou, but probably something very strong, with beautiful lines."

Muscat said he doesn't know how she'll want to dress at her wedding.

"I think it will be her, though," he said. "I think when we see it on her, we'll be like, 'It's perfectly her.'

"She knows what she wants."

Sentaler thinks Markle will continue to support Canadian designers, even after she's fully settled in London.

"Especially when it comes to outerwear," Sentaler said. "Canadians are known for coats."