Over the past couple of years, adult-oriented coloring books have become extremely popular, even to the point of becoming top sellers on Barnes and Noble and popping up on the New York Times Bestseller List. A casual review of best-selling adult coloring books on Amazon reveals everything from innocuous unicorns, flowers, cats, and fairies, to more PG and R-rated Game of Thrones-themed books and even an entire sub-genre focused entirely on swear words. And while some of these coloring books are simple titillations, many have spiritual significance as well. From Indian and Buddhist mandalas to native American dream catchers to Christian cathedral rosette windows, these books invite the colorer to focus, meditate, internalize, and relax.

Interestingly, the coloring book itself is of relatively contemporary origin. First published in the 1880’s, these simple books emerged as a result of the influence of the “democratization of art” movement in which art was seen…