One of the first psychologists who in the early twentieth century used the coloring mandalas as a relaxation technique was Carl Gustav Jung. He prescribed his patients coloring mandalas as part of the therapy.

"The golden age" of coloring books is believed to be 1960-s, because almost all characters were depicted in them, as well as some products (like Planter Peanuts or Campbell Soup)

Good Luck Charlie Coloring Pages To Print