> Do you have an actual case where it would have been useful instead of just a theoretical situation?

Yes, I am attaching the files (the 3dm as zip because it's rather heavy). The "outline" objects are not aligned and scaled to the"circle" objects, but one can see what I am shooting at.

This is part of a project that I work on with an artist. She has made a structure from porcelain. The task is to two-dimensioniolize (sp?) the thing. We opted for a halftone solution, where the levels of gray are translated into circles of different diameter for later lasering or milling.

Now I want to leave out anything that is not the object itself. So I have the circles, and the outline, and want to get rid of the rest.

Voilà!

Ditto