Apple Motion 4 - Manual (Page 880)

Use the Text Tracking parameters to modify the rate and end offset of the character
tracking. The identical Text Tracking behavior parameters appear in the Text Tracking
HUD and in the Behaviors tab of the Inspector.
Text Tracking Controls
Use the Text Tracking parameters to control the rate and end offset of the tracking
animation.
Rate: Controls the rate of the change in tracking values. The higher the rate, the greater
the tracking values.
End Offset: Offsets the end of the effect of the Tracking parameter. By default, the text
characters track to the end of the duration of the text. For example, to stop the tracking
animation 60 frames from the end of the text layer (or project), drag the End Offset slider
to 60 or enter 60 in the value slider.
Note: Be sure to use the End Offset parameter to stop the effect of the tracking behavior
before the end of the text layer (or project) rather than changing the duration of the
Tracking behavior in the mini-Timeline or Timeline. If you trim the end of the behavior,
the text snaps back to its default tracking value at the end of the behavior.
Type On Behavior
The Type On behavior quickly creates a “type-on” effect.
To use the Type On behavior
µ
Apply the Type On behavior (from the Text Animation subcategory) to the text layer.
880 Chapter 14 Animating Text