We're trying to send a version of our design to a client for quotation, but dont want them to be able to cross-section or dig into the internal workings of the design for proprietary reasons. Is there any way to save the assembly as an outer layer only?

I thought maybe using 3D PDF, but they would like to use this file in their own assembly for mechanical reasons.

Its strange, most of the stuff I download on-line are either completely solid cores or just surfaces, so I'm optimistic that someone might have an idea.

Thanks in advance.