Well, apparently they were back then and still are today for people of all ages. People are making the adult coloring books bestsellers on Amazon! At the time of this writing, eight of the top twenty books on the bestsellers list, are coloring books for adults. There must be something behind this recent growth in interest.
Coloring in a Doodle Book. You can do this very effectively by getting an artists sketch pad. This is a pad of blank sheets of paper used by artists to plan their paintings or creative work on, much like a writers rough draft. Once you have your pad, take a pencil and start to doodle. Make lines, circles, shapes, what ever at the time makes you feel good. Then color in the spaces within the doodles. Even if you think you are not a very creative person you will feel productive and relaxed after a few doodle your noodle calming sessions.
The themes of adult coloring books are usually intricate and centered more around adult images, not your childhood counterparts that included bunnies, super heroes, and farm animals. You would expect to see geometric patterns, psychedelic patterns reminiscent of doodle art type pages, fantasy images including angels, dragons, goddesses and mermaids, and ancient designs of religious and spiritual nature.