Duchess Catherine is a fan of adult colouring books.
The 34-year-old royal's husband, Prince William, has revealed his wife's love of children's hobby, which has been adapted for adults and are used as therapy.
Illustrator Johanna Bamford, who was given an OBE for contributions to art at Buckingham Palace, spoke with the 34-year-old hunk about his wife's love for colouring.
According to The Sun newspaper, she said: "I think we've just seen the colouring community flourish.
"And Prince William actually said that his wife likes to colour in the Secret Garden, which was really sweet."
The 33-year-old author's trip to Buckingham Palace has inspired her book, which is set in a palace.
She explained: "It's set in a castle, funnily enough, so I will definitely try to remember everything.
"I'm sure little snippets of today will feature in the book.
"I love all the really ornate picture frames and all the beautiful sculptures, and the candelabras are just stunning."
Catherine isn't the first celebrity to be obsessed with the colouring in craze as Kelly Osbourne uses it to cure her impatience.
Taking to Instagram, she wrote: "I finally understand why my Dad spends so much time painting! Even though this is clearly a colouring book ... it's like meditation. Before I knew it a realising hour went by and all I filled in was a bloody [leaf emoji]. I don't have very good patience and I think I just found my cure!!! (sic)"
And Justin Bieber is also a fan.