Hollow solid object keeping all faces

I’d like to 3D print some objects. Is it possible to hollow out an object and to set the width of the wall in order to reduce the amount of printing material used?

Yes it’s possible.

  1. Make B copy of body A.
  2. Shell removing outer face of body A
  3. Shell removing inner face of body B
  4. Unite bodies A and B

Thanks very much.

@ChocolateLover + @LePapa
A problem with Discourse/Forum caused me to miss this Thread previously, the plus side is that hopefully you will gain from this process.
The following is an alternative to that suggested above:

Copying is not needed. Simply select the entire body, and apply the Shell tool.