Slicing animations works in the same way that slicing single frame images works, and allows the animation to appear to load faster. Also, once an animation is sliced into individual images, each individual animation slice can be used to trigger JavaScript Rollovers and Dynamic HTML events.

As with any powerful new feature, there's a right and wrong way to use animation slicing. You'll have to be careful to slice the original image parallel to the path of the animation, not perpendicular to it. In the example above, the slices were made parallel to the path of the lightning, as you can see in the following Smart Saver screen shot:

Slicing animations in any other way can have unpredictable results, since individual slices cannot be guaranteed to download at exactly the same time, throwing off the timing of the animation. In the following example, I used both parallel and perpendicular slicing, to show how slicing animations the wrong way can cause problems:

The bottom line when slicing animations is to make sure not to slice into the moving part of the animation. Always keep your slices parallel to the movement in the animation, and your sliced animations should work out fine.