https://www.brownbagfilms.com/labs/entry/12-principles-of-animation-with-brown-bag-films-tutorial
It’s no secret that the 12 Principles of Animation are the fundamental building blocks for any animator. Get the hang of these basic techniques and you’ll be on your way to understanding the language of animation.
First introduced in The Illusion of Life by Frank Thomas and Ollie Johnston, these 12 principles have remained the quintessential roadmap for aspiring and experienced animators alike. Our animators are no exception! In fact, they have created their very own series of animation tutorials to explain the 12 Principles of Animation, using what you ask? Why, a brown bag, of course!