Caricature is the art of excess by excellence. It’s a portrait that exaggerates or distorts the essence of a person or thing to create an easily identifiable visual likeness. The cartoonist chose the memorable characteristic of person to be portrayed and explore it: expands the ears, makes the legs grow, makes the nose more accented, draws big eyes, makes the expression more dramatic, and so on. Other times the cartoonist chooses to zoomorphize the portrayed.
It’s the art of criticism, but it’s also the art of making us laugh, of making fun. Sometimes making portraits, other times anthropomorphizing animals or inanimate objects, it doesn’t matter, the point is amuse the observer, the reader. It’s not easy: requires technique, talent, exercising and hard work.
The Art of Caricaturing, by Mitchell Smith, has many tips to cartoonists wannabes. Pen lines and material, expression, exaggeration, comic figures, action, shading and shadows, technique, lettering and animals are some of the chapters of this book published in 1941 by Frederick J. Drake & Co. Publishers. It’s available on-line as a PDF, txt archive and Flip Book – the best way to take a look at.
I’m not a specialist, so I don’t know whether any information in it is outdated. It is worth for its several cartoons and plates with examples, and I don’t think that caricaturing nowadays is much different from 70 years ago.