Create new object from selected faces while retaining faces on old object I have the following model:

What I'm trying to do is for each face create a new object.  I found out how to do that here, Splitting pieces of a mesh into a new object
The problem is, that method removes the faces when I select them from the original object (refer to my screen shots)


How do I create a new object from the selected faces without taking them away from the other object?
I am doing this because I need to make another part that fits into the main object for 3D printing later.
Check this .GIF:


Select faces
Shift-D then right click to duplicate
Press P to separate