The younger the child, the larger and easier the drawing is. The outlines are indicated by a thick line from 2 to 4 mm, so that for the child it is easier to stay within the contours.

It is believed that the company The McLoughlin Brothers (en.wikipedia.org/wiki/McLoughlin_Brothers) invented the coloring books. They published a book called The Little Folks' Painting Book in collaboration with Kate Greenaway in 1880.

Corduroy Bear Printables