Hi Brian,

For the etching, you need to project to surface.

As with the example, at the stage of when you have just the one section, draw the pattern you want to cut out of the surface, make sure it is from one of the main view (it just makes it easier).



Then in the example, I have projected (curve~ project) in the right view onto the outer surface



Then its just a case of creating a pipe (whatever size you want) onto each projected curve,



The boolean them out.