Available with crayons: Most of the books come with crayons; this means that you dont have to buy them separately. If you dont know how to use wax crayons, by buying such a thing, you can always learn something new in life and relieve all the tensions that you have in your mind. You can design and color whatever you want to: While some of the books have limited designs, there are others that let you design something on your own as well. If you are more of a creative and artistic person, you might want a book that lets you be independent enough, in terms of designs.
The material. Some coloring books offer the ability for the child to simply run over the surface with the pens or crayons provided, and it will turn out to be the right color regardless. Some are more like paint books, and some have magic marker surfaces and come with markers that will not show up on any surface but the specially prepared book pages. Choose the book that best suits you and your child. If you are worried about markings on the walls, then dont select a pack of basic crayons, get something that uses special crayons. If you want your child to exercise their own creativity and not have to fit in the lines or color schemes planned, get basic pages. It is up to you.