This German Designer Explains What It's Like to Dress Kate Middleton for a Royal Tour

Thursday night, the Duchess of Cambridge took another style step in a Markus Lupfer dress. InStyle U.K. Fashion and Celebrity Director Josh Newis-Smith met the designer who found out via Instagram that Kate Middleton wore his dress to talk about the "Kate effect."

For the final night of the royal tour in Germany, the Duchess of Cambridge took on cocktail clobber in the boldest of fashions. Wearing a sparrow-printed Markus Lupfer sleeveless dress teamed with a new set of Prada heeled sandals, the Duchess showed just how to do summer occasion dressing. Attending a drinks reception in the mirrored hall of Clarchens Ballhaus, Kate made further steps into a bold way of dressing.

The dress, like many royal dress decisions before it, was another example of diplomatic dressing, given that the dress itself is designed by a German designer based in London. Here, the designer renowned for his characterful knitwear, Markus Lupfer, talks about dressing royalty and how the "Kate effect" is stronger than ever.

InStyle U.K.: When were you aware Kate had chosen to wear your dress?

Markus Lupfer: I wasn't aware she was wearing the dress until I was tagged in a picture on Instagram!

How did it feel seeing the Duchess in the dress?

I was over the moon to see the Duchess of Cambridge wearing our dress last night; she looked absolutely beautiful and so elegant. As a German born designer, based in London, seeing Catherine represent me in Berlin was a very proud moment.

Talk me through the dress.

The Duchess was wearing the Teal Bird Pleated Arabella Dress from our pre-fall 17 collection, which has just arrived online! The wild sparrow was one of our key motifs for the season. We created this print in-house, it was hand drawn and painted to create more character and personality. The Crystal pleating technique created a flattering, modern silhouette.

VIDEO: Kate Middleton Stuns in a Yellow Jenny Packham Dress

What do you think about the Duchess of Cambridge's style in general?

She is always dressed so elegantly for both casual and formal occasions. I love that she isn't afraid to experiment with prints and volumes, yet keeps her accessories neutral and sophisticated.

How powerful is it to have Kate endorsing your brand in this way?

It doesn't get much better than a princess wearing your brand. The images of her trip have appeared everywhere across Internet overnight. We are all very excited!

What are your rules for summer occasion dressing?

For me it is always about a flattering shape and an effortlessly elegant look with a twist.