Brushes are not exactly the corner stone of animating with Illustrator, but they offer some very attractive options. With brushes, you are able to simplify a very complex drawing so that it can be redrawn with a single stroke whenever necessary. That means you can take a drawing that contains dozens of elements and hundreds of points, and re-create it with as a few as two points. Also, it enables you to do transformations on that drawing by manipulating a couple points rather than having to constantly be making complex selections.
Not only that, but you can swap the brushes that are applied to a stroke thus making it very easy to change elements out for other elements.
Not only that, but if you need to make changes to the drawing, you can expand the brush's appearance to get to its component parts.
This is similar to, but not the same as working with symbols. With symbols, you are pretty much stuck with the way the drawing looks. You can stretch it , but that's about it without expanding it to its component elements.
Brushes are very easy to make and use, but they have limitations. And sometimes they do things that are just downright bizarre. But then, that's pretty much what we'd expect of anything that is remotely connected to animation.
Brushes fall into several categories, and they can all be useful for various things. Those categories are Calligraphic Brushes, Scatter Brushes, Pattern Brushes and Art Brushes. The kind of brush we are concerned with for most of our purposes is the Art Brush.
With an Art brush, you draw a stoke and apply the brush to it. Whatever drawing the brush is based on is then made to conform to that stroke. I use art brushes for arms, legs, feet, hands, fingers, props, simple creatures, clothing - anything that moves a lot and has more than minimal detail.
Creating an Art brush is very easy. You make the drawing, select it, go to the Brushes Palette options, select Make New Art Brush, give it a name and the drawing will show up in the Brushes Palette - ready to use. Okay...well, it's almost that easy, and that's what this tutorial is about.