This design wasn’t revolutionary: Children had been using coloring books since the McLoughin Brothers ... collectible-driven promotions haven’t gone away, but instead became a distinct product.

In the past few years, coloring books for adults ... it attracted us as kids. The rules are simple: Draw within the lines and use the colors you want. You can’t really go wrong when coloring.

March 30, 2011 -- Inmates at a New Jersey jail received contraband drugs hidden in paste used to color pages of children's coloring books that they ate or licked to get high, investigators say.