Taper Controls
Tapering allows you to create strokes which decrease in width. 3D Stroke has the following Taper controls:
Enable
Enable turns tapering on and off.
Compress to fit
If this checkbox is set, the tapered stroke is compressed to fit inside the Start and End sliders (from Main Controls). This option does not work with Stroke Sequentially.

Compress to fit On | Compress to fit Off

Start Thickness
Start Thickness sets the thickness at the start of the stroke. A value of zero means that the stroke will taper to a point, while a value of 1 will render a rounded edge that approximates the stroke's width.

End Thickness
End Thickness sets the thickness at the end of the stroke. A value of zero means that the stroke will taper to a point, while a value of 1 will render a rounded edge that approximates the stroke's width.

Taper Start
Taper Start controls where on the stroke tapering begins on the "Start" side. A value of 0 will begin the taper at the start of the path, while a value of 100 will begin the taper at the stroke's midpoint.
Taper End

Taper End controls where on the stroke tapering begins on the "End" side. A value of 0 will begin the taper at the start of the path, while a value of 100 will begin the taper at the stroke's midpoint.

Start Shape
Start Shape controls the shape of the tapering on the "Start" side.
End Shape
End Shape controls the shape of the tapering on the "End" side.

Step Adjust Method
This pop-up presents two alternatives for how the step size should be handled when using tapering. None means step size is fixed, which can result in the appearance of individual stamps. Dynamic means the step size is adjusted to lesser or greater values along the tapered stroke to give a precise falloff to zero without revealing any of the individual stamps. By default, this contol is set to Dynamic.

Step Adjust None | Step Adjust Dynamic