I think that’s what they’re called, the two little "| | " from the writer page?
I wonder for what reason somebody should want to do so. I would feel completely lost on a “virtual page” without any help for orientation.
Tools/Options/Libreoffice/Appearance then uncheck Text boundaries.
I’m running 5.3.1.2 on OS X. In Preferences, go to LibreOffice → Application Colors. Then uncheck Text Boundaries.
Weird that the colors section is a place where you can disable a feature.
Thanks so much for answering this question. Between this thread and the advice on how to expand a Windows cursor width, it has been a great day for customization.