I'd like to surround a path with a border (see the third illustration below). However, I cannot get it done without using
Path -> Outline stroke. This is very inconvenient, as
Outline stroke replaces the original path with a new, much more complicated one, and it becomes much harder to edit the path later.
I thought that maybe some border effect exists that I don't know of. Something like
Outer glow (see the second illustration), but solid rather than a gradient. Is there such an effect?