keynote: show / hide "guides" on slides
Keynote 9.1; MacPro 2012; Mohave (yeah, old stuff, I have to work with what I've got)
Working in Keynote, I went looking for a grid type overlay to align text elements on a single slide, a bit like what I've used in Photoshop and Lightroom for example but here for a different purpose.
What I found sounded potentially useful: "show guides" from the View menu.
It wasn't.
That added two thin horizontal lines (in yellow) on every slide as they appear in the main slide window. Trying to reverse what I had just done, I returned to the view menu and clicked "clear all guides". But nothing changed, and that makes no sense to me.
When I create a new slide from the slide menu, the lines appear there now also.
Fortunately, these horizontal lines don't appear on the images when I run the slide show, so it's not critical to my final result, but I'd prefer to be able to remove these lines.
I must be missing something. Can anyone explain this puzzle so that I can dispense with these lines?
I would be most grateful for any help.
Mac Pro, OS X 10.11