Forget the literary theatrics of Hilary Mantel or Donna Tartt.

More and more of us are turning to the simple and restorative pleasure of colouring in, with adult art storming the book charts right now.

Secret Garden, an intricate colouring book from Scottish illustrator Johanna Basford, is the bestselling title on Amazon this week, with demand for it outstripping pre-orders for Harper Lee's hotly anticipated second novel Go Set a Watchman.

The manual has sold 1.4 million copies to date and features fine black and white patterns of flora and fauna inspired by the illustrator's home region in rural Scotland.

It's not an isolated trend, either; grown-ups the world over are getting out their crayons to find solace in this childhood delight.

In Australia, friends have started to gather in "colouring circles" - like a book club, but with art. Over in France, publisher Hachette has released a collection titled Art-Thérapie, with 20 de-stress volumes featuring designs that cover everything from cupcakes to graffiti.

And here in the UK, Waterstones has reported a 300 per cent rise in sales of colouring books in the past year,

Combat stress and reinvent the joy of play with these bestselling adult colouring books