Comment 9 for bug 1506256

Thanks for the related links. Unfortunately they seem to aim at slightly different things.

There seems to be much terminology involved in things like Opacity, Translucency, Visibility, Display, Hiding, ...
I'm not really sure what fits here. My naive goal is to quickly get rid of some objects for visual reasons like:

* toggle on/off a semi transparent shadow to see if it raises readability or adds clutter
* remove random design elements to see if the overall layout is "missing" them
* see how mockups look with/without icons (that have cloned versions all over the place)

Currently I use workarounds like:
* manually drag down opacity (slow on blurred objects)
* actually grab and move them away and undo the move
* create a new object with same color as background and move it via pgup and pgdown to cover up the object
* delete the object and undo the delete