Kate Middleton Wears a Rented Dress and Princess Diana’s Choker for a Glamorous Night in Boston

The Princess of Wales knows fashion can send a message.

At tonight’s second annual Earthshot Prize in Boston, which was established by Prince William and Sir David Attenborough to award five grants annually to ideas, people, and projects aimed at combating global warming, Kate Middleton wore a green Solace London dress rented from British fashion company Hurr.

How Middleton sourced the gown spoke volumes. Instead of purchasing a brand-new gown, she opted to promote a more sustainable—and affordable—way of dressing. According to a recent report, renting clothing has decreased garment production by 1.3 million items since 2010. (67 million gallons of water and 44.2 million pounds of CO2 emissions have been saved in the process.) The “green” color, too, was a poignant one, as the shade is often the one most associated with the earth and environmental causes.

Finally, Middleton paired it with an emerald-and-diamond choker that once belonged to Princess Diana. The royal has recently opted to wear pieces that belonged to her late mother-in-law, who was also the last person to hold the Princess of Wales title. As Middleton continues to step into the role, such subtle tributes seemingly pay homage to the beloved woman before her.

The senior royal often dresses with careful intent, such as wearing local fashion designers when she travels overseas. Yet, here, the princess shows a keen understanding of “the Kate Effect,” or the tendency for her clothing to sell or spike in popularity once she publicly wears them. Now, it seems like an eco-friendly company might not only get the customer boost of a lifetime—but it may encourage buyers everywhere to think about shifting their consumer habits to less wasteful ones. Now, that’s influential dressing.