Between Heaven and Earth

Colouring Book for Adult's Relaxation Colouring used to be reserved for children and the occasional adult who got to babysit a child. However, recently, colouring has found a niche in the adult market. What started as a hobby for some, has now turned into a worldwide trend, as adult colouring books find themselves on more and more best sellers' lists throughout the world. However, while this trend may be a fun way to keep you entertained, it's the book's therapeutic properties that really have them flying off shelves.