Whether it's music, loss of something, loneliness or friendship - if that emotion is heightened in some way and painted to fit in between the covers of 32 pages, that can become a picture book.

I always try to treat the book itself as the artwork. I don't want you to stop while you're reading one of my books and say, 'Oh! What a gorgeous illustration!' I want you to stop at the end of the book and say, 'This is a good book.

If it's just brushstrokes wrestling around, it isn't much of a picture book, is it? There still has to be a picture. And maybe it needs to be a picture of a dog named Daisy or a little girl riding a bike. So I have to be careful before I get too carried away in the manner itself.

A good picture book should have events that are visually arresting - the pictures should call attention to what is happening in the story.

A man's action is only a picture book of his creed.

In a novel, you have space to develop a character or a scene. You don't have that luxury in a 700-800-word picture book.