A number of interesting effects can be produced by layering multiple envelopes on top of each other.

For example, you can create a simple ellipse, apply a large blocky square wave envelope to it, bake the resulting shape, and then apply another envelope on top of the first one, giving the square wave sides a gentle, soft wavy outline as well.

To do this, select a shape with an existing envelope, and bake it by either choosing Edit->Bake Shape Envelope menu item, or right-clicking on the shape and choosing the same menu item from the context menu. You can also press Control + B.

Now the shape has been converted to a series of curves - in effect, its previous envelope became its main strand. The disadvante is that you can no longer edit the parameters of the first envelope, but the advantage you gain is being able to edit its new, second-layer envelope.

This baking and layering can be repeated as often as is desired.

Baking Shapes and Layering Envelopes