Readjusting Master Page Margins

[MIDI Guru]

As I learn to use InDesign for formatting a novel, I'm finding that I need to change the widths of the page margins in my book (after doing a fair amount of layout work -- I don't want to start over with a new file). Oddly, the usually very helpful online help system is not telling me how to do this.

I've tried manually adjusting the frame boxes (whatever they're called) on the Master pages. That doesn't work. All it does is, on the actual pages of the book I see the newly adjusted boxes as red lines, but the type is flowing through the red lines and looks exactly as it did before.

The dialog box under Layout > Margins & Columns does exactly the same thing. The actual size of the text box on the book pages remains unaffected when I change the values in this box.

Layout > Pages > Apply Master to Pages doesn't work either. Same deal -- there are now red lines running through the text on the pages, but the actual text margins haven't changed.

This is in the latest version, if that matters.

What's the secret technique? Thanks!

[winterm]

Did You try to enable Layout Adjustment prior to changing margins on master pages?

Screenshot is from CS6, so it might be not exactly what You see.

[MIDI Guru]

That has no effect. I tried switching it on (it's a bit different in the 2017 version, as it's in the Liquid Layout toolbox). All that happens is that I get a line across the text on every page. I adjusted the top margin down radically to demonstrate this, as shown below. The line through line 8 of the text is what I get. I made this adjustment on the Master Page -- and it does nothing.

[MIDI Guru]

Sigh. I figured it out. What I have to do is use the Selection tool and then click on the Master page but NOT, repeat NOT, within the text frame on the master page. This step is cleverly not mentioned in any of the tips or documentation that I looked at. When I click outside the text box on the Master page, the margins are adjusted.

[winterm]

In general, master text frames are not very useful and thus rarely used. As far as I can see your layout, You have to stay with the majority (you didn't need it).

btw, switched to CC2017 in the meantime, just to see the differences, and didn't find much:

Layout Adjustment is still in the Margins and Columns dialog...

However, it seems like You sorted it out, and that's fine.