as described by the legendary animators Frank Thomas and Ollie Johnston

So the first principle is Squash and Stretch

This is the principle that animated objects will get longer or flatter to emphasize their speed, momentum, weight, and mass.

Here's a bouncing ball that has Squash and Stretch.

And here's one without Squash and Stretch. See the difference?

The amount that an object squashes and stretches says something about its mass

The more squash and stretch, the softer the object

the less squash and stretch, the stiffer the object

This first one looks like a water balloon and the second one probably would be a bowling ball

Squash a stretch applies to characters too.

Look at how this figure is stretching from the speed that he's coming down with.

Then he squashes after he lands, before settling in his pose.

You can also use squash and stretch to exaggerate facial expressions.

Let's add some squash and stretch to this face.

When his eyes are closed, his face is squashed, and when he opens his eyes in disbelief,

his face stretches up and settles back to normal.

It's very important to keep the volume of the object consistent.

This is what a lot of people mess up with when they're first trying to do squash and stretch.

They'll elongate the ball like this and flatten it like this.

This is what you should NOT do. the overall volume of the ball must be the SAME.

So as the ball gets longer, it also gets narrower.

When it gets flatter, it also gets wider.

The same goes with cubes. If you're going in with one line, the other lines must go in the opposite direction.

The cube should start out narrow, get flat, get narrow again, and then rest.

In-betweening with cubes is easy because you can measure the line in between the two lines and then connect them to make the cube.

If you master squash and stretch with cubes, the next step is to try to do it in 3D.

Another important note is that the ball does not have to be stretching the entire time that it's falling.

When it's just starting to fall, it should have its normal shape for the most part,

and then when it's just about to hit the bottom, that's when it has the most stretch.

So do not overdo Squash and Stretch in this sense.

Alright, that is all I've got for Squash and Stretch.

The next principle will be Anticipation.

Hope you learned something and I'll see you guys in the next video!