The bestselling book on Amazon in the US is a colouring books for adults by Scottish illustrator Johanna Basford. 
Basford’s pictures of animals and plants in Secret Garden have sold more than 1.4 million copies around the world and her next book, Enchanted Forest , has sold 226,000 copies already. The books have celebrity fans like Zooey Deschanel, who shared a link about the book with her Facebook followers, and the South Korean pop star Kim Ki-Bum, who posted an image on Instagram for his 1.6 million followers. 
“It’s been crazy. The last few weeks have been madness, but fantastic madness,” said Eleanor Blatherwick, head of sales and marketing at the books’ publisher, Laurence King. “We knew the books would be beautiful but we didn’t realize they would be such a big success.” and calm”. 
And it is not just Basford’s books that adults want to colour in. In the UK, Richard Merritt’s Art Therapy Colouring Book is in fourth place on Amazon’s bestseller lists, Millie Marotta’s Animal Kingdom – detailed pictures of animals to colour – is in seventh place and a mindfulness colouring book is in ninth place. Basford’s books are in second and eighth place – so half of Amazon. co.uk’s top ten is filled by colouring books for adults. 
Independent UK publisher Michael O’Mara has sold around 340,000 adult colouring books. Ana McLaughlin works for them. She says the craze has happened because they are telling people that the books will help them to relax. “The first book we did was in 2012, Creative Colouring for Grown-Ups . It sold well but it was in 2014 that adult colouring books became really popular with Art Therapy . We tell people they are anti-stress books so people are allowed to enjoy something they thought was childish before,” she said. 
The Mindfulness Colouring Book says that it is filled with beautiful scenes and intricate, sophisticated patterns. This makes you relax “as you fill these pages with colour”. The book suggests that people “take a few minutes, wherever you are, and colour your way to peace 
“I think it is really relaxing to unplug,” said Basford. “And it’s creative. For many people, a blank sheet of paper is very daunting; with a colouring book you just need to bring the colour. Also, people do it because they feel nostalgia for their childhoods. So many people have said to me that they used to do secret colouring in when their kids were in bed. Now, people don’t feel silly. These are books for adults. The art in my books is super intricate.” The illustrator, who lives in Aberdeenshire, is creating a third book. 
“The pictures are all over Twitter and Instagram. People are really proud of them – they are so intricate,” she said. “People send us pictures of them,” said McLaughlin.