We always thought one of Kate's strengths was her ability and willingness to recycle clothes. Kate has shown herself unafraid to spin the same frocks around the block several times, and often over several years.
In fact, you hear more people these days moaning about Kate recycling clothes, arguing duty demands she dazzle us with new choices every outing.
But Vivienne Westwood thinks she doesn't recycle enough.
"I don't have any advice to her, except I think it would be great if she wore the same clothes over and again, because that's very good for the environment and it would send out a very nice message," Westwood said at her Red Label fashion show at London Fashion Week.
"If you're going to all that trouble to get an outfit that suits you, then you should keep on wearing it," she said.
Sixty years and hardly a slip.