There are many printable coloring pages for adults available on websites such as Coloring-pages-adults.com and Colorpagesformom.com. There are also many best-selling coloring books for adults available at bookstores and websites such as Amazon.com.
The first bestselling coloring book for adults, “Secret Garden: An Inky Treasure Hunt and Coloring Book,” was released in 2013. In two years, the book sold two million copies worldwide. "Secret Garden" and the author's next book, "Enchanted Forest," occupied the number one and number two bestselling book spots on Amazon for a period of time in early 2015. Many titles feature the word "therapy" in the title and are linked with the "mindfulness" movement.