Adult coloring books seem to be the thing nowadays. I passed by Fully Booked in Cebu yesterday and they dominated the entire front display. Inside, the showcase aisle had more of them. I must have counted twenty to thirty different titles, almost all with mystical themes.
In some ways, I can see their appeal. They're whimsical and surreal, evocative of their childhood counterparts, but with a slightly darker edge. Where they differ from children's coloring books is the intricacy and the closeness of the lines. Good luck trying to fill in the lines with crayons! I must admit, though, they do look nice when they're colored well.
Adult coloring books, though, represent a desperate last stand in the losing battle that book stores are fighting. In the last few years, we've been moving away from physical books, buying less of them or -- heaven forbid! -- reading less of them. Ditto for magazines, largely supplanted now by online ad-supported articles on the Internet. If it's any indicator, Fully Booked Cebu has given up half its second floor space.
Adult coloring books still retain the necessary physicality. (There are online equivalents, of course, but they're not quite the same thing.) Physicality means a far more limited reproducibility, so customers actually have to buy the actual book instead of simply making digital copies. Adult coloring books are bought and sold like the physical goods that traditional stores are premised on.
We also can't deny the other things going for adult coloring books. They're evocative of childhood, and we all seem to feel the need to reconnect with our roots. They sell because they're viral on the Internet. They're easier to produce than books with words. Heck, they're easier and cheaper to produce than even story books because the publishers don't have to spend for color printing!
In the end, I predict they will just be another passing fad. "Adult coloring books are today's loom bands," I heard a friend say. That's the problem with virality: they spike in popularity very quickly, and almost just as quickly disappear into the discount bin.