Princess Kate’s Chic (and Totally Work-Appropriate) Tweed Dress Can Be Yours for $550

At her second official engagement since returning to work from maternity leave, it’s clear that Princess Kate hasn’t lost any of her style.

Visiting a prison Friday in Surrey, in conjunction with the addiction charity Rehabilitation of Addicted Prisoners Trust (RAPt), Kate wore a chic contemporary dress from British label The Fold.

Wearing the Eaton design in winter white tweed, the structured dress featured a semi-peplum detailing at the waist and a high soft v-neckline. Kate accessorized with a pale grey suede clutch bag from Hobbs and pale grey pumps from Jimmy Choo — an “amazing” look from head-to-toe, a Fold spokesperson tells PEOPLE.

Andrew Matthews/PA Images/Startraks

“She is the perfect ambassador for the brand, so we are thrilled — it doesn’t really get much better than the duchess!” the spokesperson says.

So how did the royal mom, 33, hear about the workwear brand, which was founded by Polly McMaster in 2011?

Kate “knew of the brand before, and every season we sent her look books,” the spokesperson says. “But this season she was particularly keen, so we sent some styles to the palace and this was the one she liked.”

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With its clean lines and simple design aesthetics, combined with luxury fabrics and tailoring, the brand is also loved by Samantha Cameron and Kim Sears, and certainly fits in with Kate’s royal work duties.

From a background in consulting and finance (and a PhD in molecular biology), McMaster has since expanded The Fold to include knitwear and less formal attire.

“I think [Kate] just liked the line in general because it’s the sort of brand that lends itself very well to these sort of events — it’s sophisticated but nothing too risky, fashion-forward but not too trendy,” the spokesperson says.

Her taste is catching: This particular dress has since sold-out (it was sent to the palace “a while ago,” their head office says), and the same Eaton dress in a similar silver tweed is currently on pre-order after every single size sold out in less than 24 hours!

—Monique Jessen