What Is an Illustration Essay? An illustration essay is usually written in a rhetorical style by using examples to support the thesis or the key idea of the essay. Illustrations are commonly used in various parts of these essays to support various points. Why Is an Illustration Essay Important? Many colleges and universities around the world give a lot of essay assignments to students at higher levels of education like graduation, masters and even doctors. Many of these essays are of illustration type. An illustration essay always gives you an opportunity to showcase your creativity with ...